What is Adobe Reader Active X?

Hello experts,
What's the difference between the other reader to this Adobe Reader Active X? For me, I think that the previous releases are way too good than this version but for some reason many people like this version so much. I've been trying hard to find the answer because if the answer is good then I need to install it and upgrade the previous version to this. Furthermore, can you give me a link where ca I download it? Thank you so much.
