Good times! Capsule history of the computer world:
Before I ever had a computer, I devoured Popular Electronics and the early computer magazines (I still have a copy of "Interface Age" that includes a "Floppy ROM" - one of those vinyl record disks that used to be bound in magazines that you play on a record player - it contained a minimal BASIC ROM encoded in the "Kansas City format" that was the most common way to save data on cassette tapes, since floppy disks (8" at the time for the small ones!) were still heinously expensive - and what hacker needed to store hundreds of KB when 64K RAM was HUGE? (Only big companies had exotic stuff like megabyte hard disks.)
These magazines featured articles about early computers from long-gone companies like IMSAI (8080), SWTPC (6800), Compucolor, Kaypro, and RCA. (Yes, they had a moderately popular early hobbyist computer board that used their own microprocessor...) It took a while for the market momentum to sort-of settle (maybe 40%) on the S-100 bus, Digital Research's CP/M operating system, and the Z-80, but early on, there were literally hundreds of different kinds of PCs, OSes, and early apps, from spreadsheets (VisiCalc and MultiPlan were the two biggest) and word Processors (WordStar was most popular) to, of course, games! CP/M was the common glue that let apps be consistent across such widely varying hardware.
I learned BASIC programming as a kid on TRS-80 model I in the first computer lab at my school in 1978. The first computer I owned was an early Timex/Sinclair ZX-81, but the first "real" computer I had wasn't until I was a senior in college, when I bought a liquidation special Commodore SX-64 - the "portable" version with a cute as buttons 5" color CRT screen and a 1541 floppy disk built in! I wrote all my senior papers and reports with it, as well as my first several resumes, using one of the most amazing hacks ever written: The amazing GEOS from Berkeley Softworks. This incredible program replicated almost all of the capabilities of the MUCH more expensive state-of-the-art Macintosh (with its far more powerful 68000 CPU) on the C-64's 64KB RAM and already pretty long in the tooth 6502 CPU. It wasn't speedy, but was fast enough to be usable, and included a word processor, calculator, spreadsheet, bitmap drawing/painting program, and more. GEOS was later ported to the PC and was used by a few companies I know of that wanted a GUI on PCs prior to Microsoft coming out with Windows in the late 80s. (I also worked at a sizeable aerospace company in those days that standardized on Digital Research's GEM OS and app suite. We did a fair amount of the automated factory design (except CAD, of course), planning, and documentation for the B-2 airframe in the GEM apps. GEM wasn't for most home users: it required an exotic VGA (640x480) graphics adapter! Interestingly, we though HDTV monitors were right around the corner then, but they wouldn't arrive for another 15 years. Our displays and interfaces still suck, compared to what they should be - think desk-sized touch/pen Surface Studio.)
By the late 80s, the PC was dominant, driven first by the 8086 (with 8087 math coprocessor if you were doing badass stuff) and later by the new and powerful Intel '286, '386, and '486 CPUs. IBM PC compatibility was becoming required, largely driven by a new upstart called Compaq making 30 lb.(!) suitcase computers - They sold like hotcakes. Very early PCs, even IBM's, gave you the choice of PC-DOS (IBM's version of what would later be MS-DOS) or CP/M-86 (the preference of us "serious and knowledgeable" computer guys - when spending someone else's money: it cost several times more than DOS!) CP/M-86 felt like a cross between CP/M and early DEC OSes - much more powerful than the clunky DOS. To do more than one thing, you had to load programs called TSRs (Terminate and Stay Resident), the most popular of which was Borland's Sidekick, which was probably the most pirated software on the planet for a while. Running multiple TSRs was possible, but they often got along like strange bulldogs in a bag... The PC software world changed forever when Lotus introduced 1-2-3, its lightning fast spreadsheet written in C, the language of serious Unix computers, which allowed nearly the speed of assembly (which was behind most commercial apps), but could be written by mere mortals who happened to be geniuses.
Macs were cool, but really expensive (like literally, the price of a new car) and more like toys than tools, unless you were doing desktop publishing, where the LaserWriter changed everything - I honestly don't think Apple would have succeeded with the Mac at all without the LaserWriter - it was that important.
Things started to get standard by the early 90s, when Windows 3 finally brought GUIs to the masses at a reasonable cost, and allowed Microsoft to extend its OS dominance into apps, where they had been a player, but not dominant. Things stayed that way until I saw a VERY interesting demo at Interop '93 (IIRC) of O'Reilly's GNN - Global Network Navigator - the first news and info website anyone had ever seen designed to work with the stunning new NCSA Mosaic browser that blew everyone away with its support for inline graphics (early web browsers required you to click on links and download the image to see it in a separate window.) It took a few more years, but that idea was the one that created the modern world, though we had to go through a few awkward years of Trumpet Winsock to add TCP/IP to Windows before Windows 97 showed up with integrated IP support.
I've skipped tons, of course, but the rest has pretty much just evolved from there into what you see today...