When performing a DCF in M&A, what value is being calculated? How long is the forecast period, typically? What is the terminal value? How are each calculated?

Should you use the target or the acquirers discount rate to calculate the value of the target to the acquirer? Does your answer differ if the acquirer and target are in different industries? What does the estimate assume about the capital structure of the target? What if you are unsure about the targets COC- what else can you do?