* Base plus offset - An absolute or indirect memory address is specified as a base address along with a register (or immediate value) that contains an offset value. The base and offset values are added together, and the resulting address is used to read/write data. This is useful for accessing arrays (where the base is the start of the array and the offset is the array index multiplied by the element size) or a device such as a memory-mapped video display (where the base is the start of the display and the offset is the character or pixel within the display). In some cases, the computed address may be written back to a register, so that as you iterate through a loop, successive data locations are accessed.* Relative - A [[Signed|signed or unsigned]] offset is added to the current [[Register#Program Counter|program counter]] to obtain a new address. This is most often used for branches or jumps but is also used for some kinds of data access. Code that uses relative addresses can be easily relocated in memory and is therefore sometimes called position-independent code (PIC).