What configuration means in practice
Configuration is the way equipment components are selected and arranged as a system. The word is useful when discussing familiarity because two sets can share a brand while using different arrangements.
An example to think through
You have used a jacket BCD but are offered a different arrangement for rental. Describe your experience to the provider and ask how the fitting and orientation will be handled before deciding whether it meets your needs.
A common misunderstanding
Recognising a logo does not establish familiarity with the configuration.
Underlying concept: PADI — Buoyancy Control Device (BCD). The example is an original YouDive study prompt, not a reported dive.