In those days , yes. PCs were IBM machines, and eventually their clones, like AMSTRAD PCs.
Sinclairs, Commodores, BBC Bs etc were known as home computers.
The main difference between them was an IBM PC was sold for business rather than home use, and it ran off a hard drive rather than off a tape, as did most of the home computers of the time.
It was running DOS as an operating system (Disk Operating System) rather than a TOS (Tape Operating System), as did most of the Home computers. Most of the home computers eventually moved up to using floppy discs when they became cheaper, but still using a modified TOS. The floppy disks were of course really floppy, generally 5 1/4 inch discs. (When they got improved into the more well known 3 1/2 inch disks in a hard case, they were still called floppy disks because Hard Disk was already taken.)
The IBM hard disks, initially having a colossal capacity of 20Mb weighed a ton (not literally), an d were quite fragile.
Another thing to note. Bill Gates bought the rights to IBM DOS 6 for his new company Microsoft, which he renamed Microsoft DOS 6.1, and the rest is history.
It's also maybe a bit cheeky having both the Acorn Electron and the BBC computer in the above list, since the BBC was an Acorn Electron in a rebadged box, and sold specifically (initially) to accompany a computer course being run on BBC2 TV.