Before we get into anything else we need a basic understanding of how a computer stores data. Inside the computer box there are many different pieces of hardware used for storing data.
One of these is the memory. A Computer’s memory is where it stores the data that is currently in use. So, for example, when you have a letter open and are looking at or working on it the computer stores it in memory. All the software currently running is stored in memory too.
RAM(Random Access Memory)Edit
This kind of memory is called RAM (Random-Access Memory). Random-access means that any part of the information may be read or changed randomly, the computer does not have to look through all the data in order so that it can find the right piece. The disadvantage of RAM is that if power goes off , the data is gone.
ROM(Read only memory)Edit
There is another kind of memory called ROM (Read-Only Memory). Read-only means that the data on it cannot be changed. ROM is used to store basic information that every computer needs.
When a computer is turned off, everything in RAM is erased. Because this would cause you to lose your work all the time, disks were created. Disks are round flat objects, but in computer slang they are pieces of data storage hardware that do not need electricity to keep the data stored. There are other things that do this that are not disks, however the things inside of all things called disks are round and flat, so that is how the term came to be. All disks need to be in another piece of hardware that acts as an interface between them and the rest of the computer called a drive.There are two main kinds of disks: Magnetic and Optical.
Magnetic disks are the old kind and are slowly being replaced by flash systems(like SSD). They store data by aligning little pieces of metal inside differently using a magnet. Because of the way they store data magnetic disks can be erased or completely destroyed by magnets, heat, and dust. The two most popular forms of magnetic disks are Hard Disks and Floppy Disks.
Hard Disk Drive(HDD)Edit
Hard disks are stored permanently inside their drive, which is normally installed into the computer box where you cannot see any part of it. Hard Disks can store a lot of data, and are used to store most of the information on computers. The advantage of HDD is cost and capacity. The disadvantage of HDD is that they create noise , are slow and prone to failure. They are slowly being replaced by solid state drives(SSD). ==== Floppy Disk Drive(FDD) Floppy disks are small disks that you can pop in and out of their drive. All you can see of their drive is a slit in the computer box with a button and a light. You can put in different disks and then take them out and give them to someone so that you can transfer data between your computers. FDD's are now obsolete. They can store only about 1.44 MB , which is way too little. They are prone to damage and are now unsupported now for many years.
The most popular kind of optical disk is the Compact Disc (CD). CDs can still be put into and taken out of their drive, making them good for buying programs on, and nowadays for transferring data. Normal CDs that you buy with programs on them are CD-ROMs. They are called that because, like ROM, they are read-only. You can also get CD-Rs and CD-RWs, which are not read-only and are not erasable and erasable, respectively. However , CD-R cannot be deleted once it is written(a process known as finalizing). CDs can store around 700MB. And, because CDs store their information with variations in the shape of the disk that reflects a laser differently they cannot be damaged as easily. However, you should still never touch the shiny surface of the CD. CD's are now being replaced by online media , and do not feature in many new computers anymore.
Digital Versatile Discs (DVDs) are another kind of Optical disc that work identically to CDs, however they can store much more information than CD's can. DVD's can store usually about 4.3 GB , but dual-layered DVD's can store up to about 9 GB and DVD-RAM can store about the same amount. They are sometimes called Digital Video Discs because of their extensive use in video and films.
Today you can also get memory cards that are called flash memory or, more properly, EEPROMs. These are cards that operate just like ROM that isn’t read-only, so they don’t lose their information when the power is cut.
SSD(Solid State disks)Edit
SSD's are based on flash memory. They are much quicker than HDD's , do not make much noise and heat , but they are costlier than HDD's , but the cost of SSD's are rapidly declining. Another concern with SSD's is that the cells on the SSD can last only up to a specific number of write cycles. However , they are not of much concern to home users , as SSD's utilize features such as TRIM to extend lifespan. The lifespan of the SSD will usually be mentioned , which could be anywhere between 30 - 150 TB , which is more than the average lifespan of the computer.
Note that defragmentation is not required on a SSD and actually not recommended , as they will not give much benefit and with reduce the lifespan instead.
Files and foldersEdit
All data on a computer is stored in collections called files and folders.
Files are the most basic data collections, they store the data for a single thing. A file is the most basic collection of data on a computer. A file can store the instructions for a single program, or the data for a single letter. Folders are collections of files. So a file is like a piece of paper and you put it in a folder.
Also called directories, folders are collections of files.
It is very necessary to sort files properly into folders so that you can find them again. Many people have had to redo entire projects because they lost their file by putting it into the wrong folder. We'll be looking at this as we go on.
Most files are named with two parts. The first part of the filename is a description of the file. After this comes a ‘.’ followed by the second part. The second part of a filename is called the extension. Extensions are often three letters long and they tell you what kind of file it is. For example ‘exe’ files (files with an extension of ‘exe’) are programs. ‘Doc’ files are Microsoft Word documents.
Note that since Windows hides the main extension by default, hackers and spammers can use this to their advantage. For instance , a spammer could send you an e-mail inviting you to open a PDF file whose filename is 'Test.pdf' and that's what you see. But in fact , it could be 'Test.jpg.exe' and clicking the file could open up viruses. You can force Windows to show all file extensions by going to Folder Options.
Besides saving (taking a file you have open in a program and writing it from memory onto a disk) there are many other file operations. These can all be done using the same program. This program is a utility called a file manager. There is a file manager that comes with Windows called Windows Explorer, or sometimes just Explorer. To open Explorer go to ‘Start->Programs->Windows Explorer’ or Right Click Start, Click Explore, and the Directory should show. Yet in Windows XP, You go ‘Start->All Programs->Accessories->Windows Explorer’.
Sometimes Explorer will start you off looking at your ‘My Documents’ folder, and sometimes it will start you off looking at drive C (C:). There are some basic parts of Windows Explorer.
- The title bar
- The main menu. Below the menu is the toolbar.
- The icon representing a folder.
- The icon representing a hard disk, also called hard drive, because the disks and the drive are in one, sealed, box, (this one is called ‘C:’, all drives have a letter).
- The icon representing a file(6) is what you click to view sub-folders.
So, if there isn’t a tree (the part in the circle) below your hard drive (which should be the icon in the left-hand pane, the part in the square, and should have a name followed by ‘(C:)’ as seen above with (4)) then click the ‘+’ (6) beside it. This is a lot of new stuff so it may be a little bit confusing.
Now we have a tree open below our hard drive showing us all the folders that are directly in the root of the hard drive. Now should be a good time to look at the standard conventions for drives and paths. As you can see above, the drive letter is always is brackets after the name of a drive. The first (or only) floppy drive is almost always ‘A:’. If you have a second floppy drive it will be ‘B:’. Your first hard drive is ‘C:’ and your CD drive is ‘D:’. If you have more hard drives the other drives change accordingly (i.e. if you have a second hard drive that is ‘D:’ and your CD drive will become ‘E:’). You can have folders inside folders as well as files, and the drive itself acts like a folder. So if you wanted to designate a file called ‘Letter.rtf’ that is in the folder ‘My Documents’ and that folder is found in the root of the hard drive ‘C:’, you separate the elements with a back-slash ‘\’ and come up with ‘C:\My Documents\Letter.rtf’.
Navigate means to make it so you are looking at that in your file manager. For example to navigate to ‘C:\My Documents’ you would open the tree on ‘C:’ like we did before (or by double-clicking on it in the right-hand pane). Then you would click the icon that is labeled ‘My Documents’, or double-click on this icon in the right-hand pane (that is, the part in the octagon).
Now navigate to your ‘My Documents’ directory. It should be found at ‘C:\My Documents’ or ‘C:\Documents and Settings\[Your Name]\My Documents’. Now, to open a file in its program, double-click on its icon in the right-hand pane.
If you accidentally delete a file you wanted, you can open the Recycle Bin (double-click on its desktop icon) right-click on the file and select ‘restore’ from the popup-menu. If you want to permanently get rid of all files in the Recycle Bin, right-click on the Recycle Bin and select ‘Empty Recycle Bin’ from the popup-menu. Deleting or restoring folders works the same way.
Sorting your filesEdit
If you are going to sort your files properly into folders, you need to know how to create them. To create a folder, navigate to the folder you want the new folder in. Then, right-click on a blank area of the right-hand pane to bring up the popup-menu.Then select ‘New->Folder’ from the menu. Type the name of the folder and press ‘Enter’. To arrange file in folders, you also need to be able to copy and move both files and folders. Moving means that the file or folder goes to the new location and is no longer in the old location. To move a file or folder, simply drag-and-drop the file or folder from where it is in the right-hand pane on top of the folder where you want it to be in either the right or left-hand pane. Copying means that the file or folder stays where it is, and a duplicate is created in the new location. To copy a file or folder you right-drag-and-drop (that is, drag-and-drop by holding down the right mouse button instead of the left one) from its old location on top of the new one. A popup-menu will come up asking if you want to copy, move, or create a shortcut to the file or folder. If you want to copy, select ‘Copy Here’.
If you want to search the whole computer for a specific file or folder there are two possible ways to do it. Some versions of Windows Explorer have a button on the toolbar that says ‘Find’, click on this. In all versions of Windows you can go to ‘Start->Find->Files or Folders’ or ‘Start->Search’. Some versions of the search have extra features to make it easier that it displays first. To bypass these click ‘All files and folders’. If your version came up with text boxes right away you don’t have to do this. Once the text boxes are up you can select what drive or folder to search from the combo box. The topmost text box is where you type all or part of the filename.
You can also create wildcard searches. To do this you type letters that are in the filename along with symbols called wildcards. The wildcards are ‘*’ and ‘?’. ‘*’ represents an infinite number of characters or nothing. ‘?’ represents exactly one character. So ‘?ello.doc’ would find ‘Hello.doc’ and ‘jello.doc’. ‘Si*.*’ would find all files that start with ‘Si’.
Finally there are file properties. Different kinds of files have different properties and different versions of Windows can have different kinds of properties allowed. You can experiment with these if you want. To open the properties for any file, right-click on it and select ‘Properties’. In the window that comes up you can change all the properties of the file that can be changed. In this window it also shows the name and location of the file and its size in bytes, kilobytes (KB, 1 024 bytes, usually estimated at 1 000 bytes), or megabytes. It also shows the attributes, the most commonly used and useful of which is the read-only attribute. When you check the read-only check box and click OK, Windows won’t let any program change the file. If you uncheck the box Windows will let programs change it again. This operation can also be done using the 'attrib' command in Command Prompt.