Different boot disks and later different menu items in configsys and autoexecbat to control which drivers were loaded and where (himem etc) to launch different

Different boot disks and later different menu items in configsys and autoexecbat to control which drivers were loaded and where (himem etc) to launch different games I don’t recall how it was all figured out int he days before modems. I remember dos came with a nice chunky set of manuals, I guess games might have had information in there too, but I for one don’t really understand the different between high and low in the first megabyte, or between extended and expanded memory, or what an Irq really was, I just knew you had to live the jumpers on the sound card - which I assume I got from the manual.