The fundamental unit of yasm assembly. Usually represents a single machine instruction or assembler psuedo-instruction, stored in an expanded format that includes assembler state information such as length, source line number, etc. It can store duplicates in a compressed format by storing only the number of multiples.

A contiguous memory area. Represented in yasm as a single list of bytecodes, a list of relocations, and a number of section-level flags. Generally a yasm section maps directly into a object file section.

See Section.