Overlock seaming was invented by Merrow Machine Company back in 1800's. To this day many industrial or professional "serger" machines or overlock stitching is called "Merrow".
Overlock stitching either done on a dedicated machine (industrial) or domestic sewing machine sews over two edges of fabric producing a strong seam that also prevents edges from fraying among other things.
True merrow or overlock stitching uses loopers to create stitches. Domestic sewing machines will use some version of a lockstitch which may suffice depending upon what is desired or wanted.
https://en.wikipedia.org/wiki/Overlock
A serger machine is one with a knife that also cuts edge of fabric while creating seam. Obviously this cannot be done with a domestic home lockstitch machine.
As with nearly every other stich done by machine overlock can (and was long done) by hand. It's tedious work but there you are.
Does average home sewer (or anyone else) actually need a dedicated serger/overlock machine? That is a debatable point.
Going back to 1950's or maybe sometime in 1940's when first European sewing machine makers such as Necchi introduced zig-zag stitching it became possible to finish edges of fabric by "overlocking" simply using a variation of that stitch.
Modern sewing machines since say 1960's or so and certainly today from likes of Singer, Bernina and so forth offer overlock and some other stitches that match what can be done with a dedicated overlock machine to an extent. Things like rolled hems can also be done using sewing machine.
Serger/overlock machines came into their own for domestic sewers with rise of modern stretch/knits, polar fleece and some other fabrics.
T-shirts, undergarments, swim/beach wear.. All sorts of things made from knit fabrics can be sewn entirely with flatlock or cover stitch.
https://www.letsgosew.com/joanne-bankos-blog/fast-flat-serger-t-shirt-and-sewing-machine-tips-too
https://weallsew.com/overlocker-for... stitch that,the stitching and looper threads.
https://www.heirloomcreations.net/what-is-a-coverstitch/
Blind hemming is similar. One can do that work on a sewing machine, by hand or with a dedicated blindstich machine. Depending upon how much of blind hemming one does on routine basis it may not make sense to have a dedicated machine.