Clarity on "backoff" type in relation to "delay" in ISM policies

Plugins Index Management
1

Hi! As I was reading the documentation on ISM policies and configuring retries for them:

I am a little confused on the meaning of “backoff” and “delay” in this context. If a “delay” of 1 minute is set does this delay increase with each iteration if backoff type is defined as “exponential”? Or does this refer to some other process?

Sorry if this is obvious I’m just a little confused.