1. Explorer 10
1.1. Pros
1.1.1. Offers add-ons for better browsing experience
1.1.2. New versions of internet explorer have download manager along with malware protection.
1.2. Cons
1.2.1. Some version does not support java script enable websites, blogs/forum,internet explorer.
1.2.2. Old version only support windows xp and does not support window vista: Window 8. You need to install IE10+ to run on window 7 & window 8
2. Chrome27
2.1. Pros
2.1.1. Chrome also allows Google users to sync their accounts, which comes with added benefits like restoring saved bookmarks and extensions in the cloud no matter what device you're on.
2.1.2. It's really fast-The program itself opens within seconds of when you click the icon, too--a distinct advantage over some slower-loading alternatives.
2.2. Cons
2.2.1. It's only in its first beta-run a risk by putting your online life into the hands of an unproven product.
2.2.2. You lose some history power-The ability to sort everything by date, site, or most visited appear to have joined the distaff and spindle on the ash heap.
3. FireFox 21
3.1. Pros
3.1.1. Good HTML5 support. Good security. Most cross-platform support. Social network integration via API.
3.1.2. Host of developer tools. Compatible with MacBook Retina displays.
3.2. Cons
3.2.1. Lacks client-side tracking protection like that found in IE9.
3.2.2. Lacks Chrome's built in Flash and Instant page view.
4. Safari 5
4.1. Pros
4.1.1. Elegant UI with Cover Flow, fast performance and browsing speed
4.1.2. easy access to most visited pages, build in RSS reader, best for MAC OS.
4.2. Cons
4.2.1. Add-ons limited and not useful, heavy memory and system requirements.
4.2.2. font resizing in Reader not possible.
5. Opera 12.14
5.1. Pros
5.1.1. Opera is a slick, small, fast and secure email client and RSS feed reader
5.1.2. Mail shows up in all relevant places automatically and can be searched with speed in Opera
5.2. Cons
5.2.1. Opera does not offer flexible message templates or advanced automation
5.2.2. Secure message signing and encryption are not supported by Opera
6. Definitions
6.1. Browsers
6.1.1. Is a software application for retrieving, presenting and traversing information resources on the World Wide Web
6.2. Plug-Ins or Extensions
6.2.1. a plug-in (or plugin, extension) is a software component that adds a specific feature to an existing software application.