What an online configurator does
You pick parts one category at a time, and after each choice the remaining lists narrow to the components that fit what you have already selected, physically and electrically. Nothing has to be memorised: the socket, memory type, case dimensions and power connectors are checked as you go, so a combination that does not fit is simply never offered.
Start with the purpose, not the parts
First decide what the PC is for and at what resolution: office work and study, gaming at 1080p, 1440p or 4K, or creative work. The resolution sets how much is worth spending on the graphics card, and the purpose sets whether you need more cores, more memory or more disk space. Ready-made builds by purpose are a quick starting point you can change afterwards.
The order that saves time
Start with the platform - processor, motherboard and memory belong together, because this is where the socket and the DDR generation are settled. Then the graphics card, because it drives both the price and the power draw more than anything else. Case, power supply and cooling come last: they have to swallow everything already chosen - card length, cooler height, radiator mounting points.
What the configurator checks for you
The compatibility check covers the processor socket and chipset, the memory type, the number of modules and the maximum capacity, the board format against the case, graphics card length and cooler height, radiator mounting points, M.2 slots and SATA ports for drives, the power supply format and length, and the EPS and PCIe connectors the parts demand. Errors block the build; warnings - a tight clearance for the card, say, or a board that may need a BIOS update - are left to your judgement.
Estimate the performance before you buy
Gaming performance comes down to the processor and graphics card pairing: the result is always the lower of the two ceilings. Check the estimate for your chosen pair at your resolution and settings in the FPS calculator - if the numbers are too low, a different graphics card usually helps the most.
Compare offers and order
Next to every part you see offers from the shops that list it - we do not sell parts ourselves, you order straight from the retailer. If any doubt remains about power supply wattage, a separate calculator shows the recommended number of watts for your build.