How long does it take for a transaction to confirm? What is required for this process?
Around 7 seconds in the new Chrysalis Network. See here: https://chrysalis.thetangle.org/
According to https://chrysalis.thetangle.org/ the current confirmation time is around 7 seconds. In a pre-Coordicide network this completely depends on the milestone interval which is currently set at 10 seconds but can be changed at anytime by the Coordinator (ie. the IOTA Foundation).