Subversion is a version control system. The purpose of using such a system is that you can easily keep track of many different versions of your software system. In addition, the system helps you work on the same project from many different places (and in company settings in a distributed manner).

You should check in your homework solutions every time you finish working on a problem.

You can check whether your homework is visible by pointing your Web browser at

http://svn.barzilay.org/107/pairNNN

for your number NNN. The browser will prompt you for a username and a password and, if these are correct, will display your directory structure as a Web page. Just like the design recipe asks you to run tests at the end of a design cycle, you should -- no you must -- check on your homework assignment on the server whenever you think you're done.