Liquid is an exchange site built on Bitcoin, just like the Lightning Network.
Users who make a deposit on Bitcoin and open an account can make transactions on each other using this deposit and form the base of the new system. Thus, they can directly make millions of transactions without creating a burden on the BTC network.
Like every crypto exchange, Liquid was hacked and thousands of people's information and money stolen. Fortunately, the system got better in a short time.
Mining is not possible in Liquid. With this structure, it has a completely different system from Bitcoin. Since Bitcoin is an open network, all users can easily enter and exit the system.
Liquid's most basic and distinctive feature: It does not keep your money in the stock market. So if your asset is in the stock market, it is always a clear target. This is where Liquid comes into play. You keep your money in L-BTC and you can transfer it to the stock market very quickly and trade immediately. This is good for security.