"Intellectual Property" is an all-encompassing term that covers patents, copyright, and trademarks. The "IP" that your CIO is talking about is the copyright of your program. Basically, the company is making a claim of ownership of that code since you developed it on company time (ie: "Work For Hire"). The basic idea of copyright is that you own your own works unless you assign those rights to another person (or company). However, in an employement relationship, the "author" of the work is the company. Also, you'd need to review any employment contracts and such that you signed with the company regarding assignment of IP. Lots of companies make you pretty much assign to them anything you develop during the time you're employed by them to the company - even stuff that you do on your own time and has zero connection to the company in any way. Regarding what you can or can't do on the side, the answer is "it depends" on whether or not you have any non-compete or assignment of rights agreements with the company you work at. It's really important to read anything you sign and keep copies.