Parse Path and Compose Path allow for greater automation with models but Compose Path only combines parts, such as folder, file name, extension, etc. and doesn't handle a custom user string.
The Concatenate process will accept two strings, append the second to the first, then output the combined string. This value can then be fed into a corresponding Compose Path. For example, existing input file names can now be used as the basis for a new output file name with a suffix attached to it.