No, you don't need Adobe Acrobat to be able to use Adobe Reader, it's a stand-alone application.

Adobe Reader is simply for viewing and printing PDF files. You can zoom in and out, adjust the way you view the page and select text, but that's about it. As it's name suggests, it's basically for reading only.

If you want to create PDF files using Adobe software, then you'll need Adobe Acrobat -- which also lets you edit, secure and markup PDFs. However, there are many other non-Adobe solutions out there that will let you create PDFs as well -- some of them are free tools and some of them are commercial products.

Adobe Reader isn't the only free PDF viewer either. Foxit Reader is one popular alternative.