some IEs version and its files version

In Forum: Microsoft Operating Systems
By User: w310901

4.40.308 IE1(plus! for for win95)
4.40.520 IE2
4.70.1155 IE3
4.70.1158 IE3.0(win95 OSR2)
4.70.1215 IE3.01
4.70.1300 IE3.02 and IE3.02a
4.71.1712.4 IE4
4.72.2106.8 IE4.01
5.00.2014.0216 IE5
5.50.4134.0600 IE5.5
6.00.2800.0000. IE6(XP)

I don't know why the Files version don't begin with 1.xx.xx as the IE version,and what's the relationship btween IE and its files version?