The 20-22 nucleotide region will vary based on the target DNA, but will never include the PAM (NNGRRT, N = any, R = A or G) sequence. The PAM sequence is located on the target DNA, just 3´ to the non-targeted DNA strand in the target region.
An example can be found below. The bottom strand of the dsDNA in this example is the target strand. The PAM (NNGRRT, or in this example ACGGAT) is found on the non-targeted strand just 3´ to the target sequence.