Plug-in : an application that adds a specific feature to a program.
Adobe Flash Player : an application that allows the user to display multimedia on Web browsers.
Adobe Acrobat Reader : an application that allows the user to display Portable Document Format (PDF) files on a Web browser.
Microsoft Silverlight : an application that allows a user to use video sites on a Web browser.
Pop-up blocker : a program that prevents pop-up windows from appearing on a Website.
A pop-up is an online advertising that uses a new window for display.
Browser cache : a temporary storage of Web data.
The main purpose of a browser cache is to speed up Internet surfing by saving Web data, so that when the user tries to go back to recently visited Web pages, the browser displays them instead of downloading them again.
Cookies : small pieces of data exchanged between the Web browser and the Web server that store information about the user.
The main purpose of a cookie is to identify the user, prepare custom Web pages and save site login information in order to provide recommendations for the user.