So a ACME thread is a form of "Trapezoidal" thread but is cut at 29 degrees and will be in Imperial dimension and pretty much always be refereed to as an ACME thread. The term "Trapezoidal" thread is applied to Metric dimension threads and will have 30 degree included angle. There is also a variation in the metric trapezoidal thread depending on the DIN specification.
ACME and Trapezodial threads are used for the same things - leads screws etc just one is metric and one is Imperial