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 using the EXPORT directive.

The address given by a label is calculated during assembly. The assembler calculates 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 addressing.

Addresses of labels in other sections are calculated at link time, when the linker has allocated specific locations in memory for each section.