Skunk, do the honors.
With pleasure!
Mixers have been in existence all along as a summing medium, where all the signals from the individual channels are "mixed" into a master bus. All throughout history, mixers have gone larger and larger to accommodate more inputs (both line and mic), with more aux sends and subgroups, fx loops, patchbays, blah blah, to have more flexibility in mixing whether in a live or studio context.
But the rise of ITB mixing has somewhat lessened the popularity of mixing in the console. Arguably, using and abusing plugins can rival a true mixing console, but then again, some people prefer using a Neve, SSL, Amek or whatnot because of their household name reputation.