Mimeograph aka spirit duplicator used a stencil that you could write on or type on and then use alcohol to then dissolve the raised part of the stencil and transfer it onto the paper. It worked well for simple stuff but kinda poorly for halftones and could prob only provide 300 copies before you'd need a new stencil.

Xerographic from Greek "dry writing" differs in that you use a fine powder (toner) that can be electrostatically charged and then drawn to paper using a light-sensitive drum.

The genius of the AM machine is that it could be used to print on practically any medium including metal, dogtags were printed in this way. Also, data could be saved in either punchcard format or later electronically. The last big use was for imprinting credit cards.