Borrowing allows a user to lock Eth as liquidity and borrow debt in the form of a token called Hue. If you are unfamiliar with defi debt on the blockchain, check out And what is lending in defi anyways?
Users can create a Hue loan overcollateralized with Eth. In simple terms, this means that in order for someone to mint Hue, they need to lock a greater value of Eth into the protocol. Eth provided to TCP is always owned by the user that provided it (as long as the position is safely collateralized), and can be received back at any time by paying back the loan plus any accrued interest. Note that interest can be positive or negative, so it's possible to owe less than you borrowed! Learn more in Interest Rates.
Test out the protocol here! https://rinkeby-tcp.on.fleek.co/
Users who participate in borrow during the genesis period receive an equal amount of TCP regardless of the total value they have borrowed. This ensures that TCP is distributed to those that support the protocol as opposed to only those that are rich.
At launch, positions must have either zero Hue debt, or at least 100 Hue debt. This is to ensure that there is an incentive to liquidate any position. The community can decide to update this requirement if they choose.
Each Hue token is backed by a greater value of Eth. The minimum collateralization ratio at launch is 150%. This means that for every Hue in circulation, there is Eth worth at least 1.5 Hue locked into TCP.
Overcollateralization makes it so that if the value of Eth decreases, positions can be liquidated, with an incentive from the overcollateralization to the liquidator, before the protocol as a whole becomes undercollateralized. The protocol is considered to be "undercollateralized" when each Hue token is backed by less than 1 Hue worth of Eth.
Due to instant liquidations, the amount of overcollateralization the protocol requires is reduced. This is because positions can be corrected as soon as they become even slightly undercollateralized, decreasing the risk that the protocol as a whole would become undercollateralized. This can happen when liquidations take hours or days due to using an auction mechanism. Therefore, once the protocol is launched and everything is working properly, the community can safely decide to lower the collateralization requirement. This makes TCP more capital efficient.