The Intel Core i5-10600K is a mid-range processor for desktops with six cores based on the Comet Lake architecture (CML-S, 4th generation of Skylake). The processor clocks at between 4.1 and 4.8 GHz and can execute up to twelfe threads simultaneously thanks to Hyper-Threading.
The processor is still manufactured in the old 14nm (14nm++) process. Thanks to the free multiplicator, the CPU can also be easily overclocked (but may not have much headroom).
The Comet Lake architecture is similar to Coffee Lake and offers the same features and is produced in the same 14nm process. Other than the improved clock rates, the memory controller now also supports faster DDR4-2933 RAM. More information on Comet Lake and all the models and articles on it can be found here.
Thanks to the high clock speeds (and possible TDP settings with most mainboards), the Core i5-10600K offers a similar speed than the old Core i7-9700K quad core. Compared to current AMD offerings, the multi-core performance is on par with a Ryzen 5 3600, single core and gaming performance with a faster Ryzen 9 3900.
The integrated Intel UHD Graphics 630 iGPU is supposed to offer a similar performance as the UHD630 in the Core i7-9900K. As a low-end solution it will only run current games smoothly at reduced details - if at all.
Intel specifies the TDP with 125 Watts (PL1) but under full load up to 250 Watt are consumed (PL2). In default mode these 250 Watt and therefore high clock speeds can be maintained for up to 56 seconds, however, all boards offer the option to alter these settings.