Complex sentence: The register machine gets its name from its one or more "registers"--in place of a Turing machine's tape and head (or tapes and heads) the model uses multiple, uniquely addressed registers, each of which holds a single positive integer.
Split into simpler sentences: The register machine gets its name from its one or more "registers". In place of a Turing machine's tape and head (or tapes and heads), the model uses multiple, uniquely addressed registers, each of which holds a single positive integer.