A few blogs back, I covered why you should get a decent motherboard. Now, I’ll go over power supplies.
what is a power supply
If the motherboard is the central command center, the CPU is the resident expert, and the GPU is the part most important for Gaming PCs, then Power Supply Units (PSUs) are what keeps everything running. You could loosely relate a PSU to a gas tank in a car.
Desktop Computers run off DC power, much like most of your electronics. If you put a 120V AC line straight into a PC, it would explode in spectacular fashion. PSUs convert that 120V AC socket off your wall into whatever DC wattage you need to run your PC. This wattage can be calculated with online calculators, you simply select what components you want, and pick a PSU that works.
a bit of advice
Typically, I would advise getting a PSU with at least 100W more than you currently need. This allows for easy overclocking, as well as potential additions to your PC.
The 80+ Bronze, Silver, Gold, Platinum, and Titanium denotes the efficiency of the PSU. In other words, a higher-rated unit will draw closer to the desired wattage, where a lower-rated unit will draw more...and thus be less efficient. Higher-rated units end up costing you less in utilities/year.
The non-modular, semi-modular, and fully-modular relates to how the cables are bundled. These range from all of the cables being bundled together, and looking like a hot mess...to the designer having to connect only each cable that is necessary. Fully modular tends to cost more, as it is much better for cable management, and is more stylish. Fully modular also allows the user to purchase custom cables, with different color schemes.
You need to to invest a good chunk into a reputable brand (EVGA, SeaSonic, Corsair), as the PSU is a likely culprit in the event of a random loss of power, or an inability to boot. If you see LEDs turn on, and fans spin up, but no real “engage”...you probably have bad connections, or a bad PSU. Higher-end PSUs have undergone more stringent testing, and are less likely to fail.
You wouldn’t run a racecar on low-end gas...so why would you outfit a high-end PC with a subpar PSU?