Labels are symbols representing the memory addresses of instructions
or data. The address can be PC-relative, register-relative, or absolute.
Labels are local to the source file unless you make them global
The address given by a label is calculated during assembly.
the address of a label relative to the origin of the section where
the label is defined. A reference to a label within the same section
can use the PC plus or minus an offset. This is called PC-relative
Addresses of labels in other sections are calculated at link time, when the linker has allocated specific locations in memory for each section.