I'm working through Expenses example in the Dev Guide and see "v." and "c." in several locations but they aren't things that are declare anywhere.

Are these well-known objects that have to be referenced via "v" and "c"?  Like mayb "v" is view and "c" is controller" or something like that?

I'm curious if the code could be altered and the "v." and "c." terms could be changed if they are declared somewhere or if I'm coding in this style, must I use objects referred to by the specific named "v" and "c".