I.E is a short version for Internet Explorer. A easy-to-use microsoft tool. It browses the web, with maximum security, and operating tools, such as view source ECT.
From the time i am writing this, the latest version is I.E 7, there is no difference from the outside, but there is in the inside (which u cant see or notice at that)
I use the latest version of I.E to browse the web quicker, and safer.