difference between #include formats

Usually, when I am importing code to a program, I use the usual #include <SomeLibrary.h);
but I notice that the compiler sometimes requires #include “SomeLibrary.h”. What is the distinction between these formats, and does an “.h” file always need the associated “.cpp” file? I find that Sparkfun supplies a “.h” file for the Nokia 5110, but there is no associated “.cpp” file, and, although their example program compiles, it does nothing.

Thanks in advance for any assistance with this.

The convention is that the angle brackets (<>) cause the compiler to search the default header directory first. The double-quotes causes the compiler to search the current source code directory first and then search the default directory if the header file is not located.