PC means “Personal Computer”. In 1973 Xerox Alto was the first computer to use a mouse and a graphical interface. One of the first PC for the public was the Altair 8800. It came out in 1975 by the company MITS. It had a 8 bit processor with a 2mhz speed. No display, mouse or keyboard. Only a switch and a display lights. It was affordable (around 400$).
Microsoft was founded in 1975 by Bill Gates and Paul G. Allen after they worked on the Altair 8800. The apple I came out in 1976 for 666,66$. It could work on a TV monitor and had no case or keyboard. 4KB memory.
Apple launched Apple II in 1977 for around 1298$. It had a great success and the PC market exploded which led to the development of other companies to release their own models. Apple could store on floppy disks (140kb). In 1981, IBM releases the IBM PC with a 16-bit processor, the Intel 8088. It ran on MS-DOS, the first OS released by Microsoft.
Microcomputer, Apple II. CPU and keyboard, 1990.0167.01.1. Monitor, 1990.0167.01.2. Disk drive, 1990.0167.02. 
Then came out the Commodore 64 in 1981 for around 595$. One of the biggest success in the industry with more than 12 millions units sold. It had a 1MHZProcessor, 64KB RAM and 20KB ROM. Also in 1981, came out the first laptop on the market, the Osborne1 which weighted 11kg and costed around 1795$.
In 1982, IBM accepted that MS-DOS is no longer exclusively on IBM PCs. The PC market is then invaded with IBM clones. In 1985, Windows 1.0, a GUI for MS-DOS is released. In 1986, more than 50% of the PCs sold are IBM or clones.
In 1984, Apple releases Macintosh. Steve Jobs quits Apple in 1985. In 1987, Apple releases its first PC with colour display, the Macintosh II. The first Apple laptop is released in 1989, weighs 7.2KG and costs 7300$.
Title/Inv.:1999-1010_(0002) Photographer: Daniele Melgiovanni Science Museum Date: 22/07/05 Colour Profile: Adobe RGB (1998) Gamma Setting: 2.2
in 1990, Windows 3.0 is released. The first Linux core is created in 1991, in this exact same day!, by a Finland student, Linus Torvalds. In 1992, Windows 3.1 is released and becomes quickly the most popular OS on PCs. The Intel Pentium processor is released in 1993 with a speed of 60MHZ.
In 1995, Windows 95 is released with a 32-bit architecture. Steve Jobs is back at Apple in 1997 which is the only company releasing PCs with Mac OS. Windows 98 is released at the same time Apple announces the iMac G3. Intel Pentium III is released in 1999 and their competition AMD, announces the Athlon processors with a 1GHz capacity in 2000.
The “parts”
Processor(CPU): The calculating unit, executes commands and programs. The PC’s brain.\
Motherboard: connects and controls every parts with the BIOS. The spine of a PC.
Memory(RAM): Stores processes, running programs and the OS for a quick access. The PC’s short term memory.
Hard Disk Drive/Solid State Drive(HDD/SSD): Stores the data in a slower way than RAM. The PC’s long term memory.
Power Supply Unit(PSU): Brings the electricity to every part of the PC. The heart of the PC.
Graphic Processor Unit(GPU): Generates the video display with high calculating power for simple tasks.
Sound Card: Brings the audio functionalities. Most of the time it is integrated in the motherboard.
Network Interface: Allows to communicate on a network. Mostly integrated in the motherboard.
Case: Protects the PC parts from the outside elements and provides air flow for the heat generated by the parts.
Optical Drive: DVD or Blu-Ray
Display Monitor: Displays the image for the user.
Shoutout to my teacher VGR for this history lesson!