The Technology Layer depicts: 

- technology (/ infrastructure) services such as processing, storage, and communication services needed to run the applications and the technology components that realize them 

- the SBB's, i.c. computer and communication hardware and system software that realize those services. Physical elements are added for modeling physical equipment, materials, and distribution networks to this layer.

Source: pubs.opengroup.org/architecture/archimate3-doc/chap03.html​​