What does a virtual function really do?

[nooblet001]

Hello. I'm confused on what a virtual function really does. So far, I've learned that a virtual function lets the computer decide which function to execute based on the data type at run time. For example, 2 classes(a base and derived) having 2 same functions names.

[MiiNiPaa]

These articles can be helpful to you:
http://www.learncpp.com/cpp-tutorial/124-early-binding-and-late-binding/
http://www.learncpp.com/cpp-tutorial/125-the-virtual-table/