Export iPhone or iPad Backup to an external hard drive
Yes - Apple documents the folder in which iTunes saves backups here:


https://support.apple.com/en-us/HT204215


Apple doesn't make tools to poke at those files and export the data, however.

The apps themselves are saved in the iTunes library - so you can move them easily. The data embedded in apps depend on how the developer of that app chose to store them. Many use sqlite and xml and other standard data formats, so it's not unreasonable to get at many of the files - some are even stored with odd names, but still the correct image and sound and movie file formats.