chipmixer, is it some kind of chip for gaming? or what?
Not for gaming but analogy is correct. Chip like casino chip. You trade banknote marked by serial number for non marked casino chip. Then you trade casino chip for another banknote making your transaction non visible at blockchain.
ChipMixer creates Bitcoin addresses (chips) and funds them with specific sizes. There are chips with 0.001 BTC, 0.002 BTC, 0.004 BTC and so on till 4.096 BTC. When you deposit your Bitcoins, you receive same amount in chips. For example you deposit 0.112 BTC and you receive 0.064 + 0.032 + 0.016. Each chip was funded before your deposit, so there is no link between them and your deposit on blockchain. They are already anonymous. With each chip, you receive its private key, so you can spend them any time you want.