Is there software that allows you to sort of draw up object oriented code dependencies like you could with a white board but better cause you can move things around and change stuff easy and save to file? I'm about to start a large project in c++ and I'm thinking about how to design my objects and what objects go inside of other objects, but I don't even know what software like this would be called? (so I can't google, object oriented design comes up with to much junk) Free or open source would be best if it exists thank you for reading.

Is there software that allows you to sort of draw up object oriented code dependencies like you could with a white board but better cause you can move things around and change stuff easy and save to file? I'm about to start a large project in c++ and I'm thinking about how to design my objects and what objects go inside of other objects, but I don't even know what software like this would be called? (so I can't google, object oriented design comes up with to much junk) Free or open source would be best if it exists thank you for reading.

You're probably thinking about some form of UML editor.
http://en.wikipedia.org/wiki/Unified_Modeling_Language
http://en.wikipedia.org/wiki/List_of_Unified_Modeling_Language_tools

I'm a big fan of lucid chart. It's online, which is nice since it lets me use my various computers, it's pretty easy to use (I got lost in my first few UML programs), it's pretty powerful (I've done program flows, program class designs, and even processor flow charts), it's made by a GDNet local (BeanDog), and it's got free pro-level accounts for students.