Can someone explain the difference between staking for CPU and staking for Net Bandwidth?
CPU is measured in microseconds and your stake determines how many microseconds of time a producer should spend processing transactions from your account. This is measured subjectively by the producer that includes the transaction in the block.
Net is measured in bytes and your stake determines what share of a blocks' network representation can be used to store your transactions as they transmit on the P2P layer.
As these two resource classes are not necessarily related the resource pools are different.
In both cases, you have some burst capacity and if the chain is relatively idle, you can consume more than your proportional share (until it gets more congested)