Membrane vs rubber dome

The terms "membrane keyboard" and "rubber dome keyboard" are frequently interchanged, because most modern keyboards use both, in the form of rubber dome over membrane. However, the two concepts are distinct and many keyboards use one and not the other.

Rubber dome keyboard

A keyboard which has rubber domes inside each key. The rubber dome provides tactility, and it actuates the switch using pressure or conductivity.

Membrane keyboard

A keyboard which places electrical contacts on plastic membrane sheets

Switch types

Membrane and rubber dome These are typically keyboards where two outer membrane sheets, separated by a third, are squeezed together under the pressure of a rubber dome. Examples: Most consumer and office keyboards since the mid 1990s All scissor switch keyboards	Membrane but not rubber dome These are typically keyboards where pressure is applied to the membrane sheets using a metal spring, sometimes with a plastic hammer on the bottom. Examples: Membrane buckling spring (e.g. IBM Model M) Acer switch Cherry MY Alps spring over membrane
Rubber dome but not membrane Switches which make use of rubber domes without having membrane sheets; this includes capacitive sensing and conductive domes. Examples: Topre switch Alps integrated dome	Neither rubber dome nor membrane Most vintage switches used neither domes nor membrane sheets; a variety of other switching mechanisms have been designed over the decades. Examples: Metal contact switches Hall effect switches Linear capacitive switches