Plasma is one of the Layer 2 solutions. It was first proposed in 2017 to solve the transaction speed and cost problems of Ethereum, and it is also the first solution in the Ethereum community to try to solve such problems.
In order to improve transaction throughput, Plasma compresses multiple transactions into one block, and offloads the calculation and storage of transactions off Ethereum mainnet (e.g. Layer 1) into Plasma chains. Compressed data will be submitted to Layer 1, and if disputes arise during the process, Plasma will use fraud proof to arbitrate to ensure safety.
In theory, Plasma can increase the TPS of Ethereum to 1-9k, but in actual development, many problems have been exposed, such as the period for users to withdraw funds from it is too long, and all users are required to monitor all transactions on the Plasma chain. As a scaling solution, Plasma-based implementations continue to be explored.