Adaptive State Sharding is a method of increasing the throughput and scalability of a blockchain network by dividing the network into smaller, parallel subnets called "shards."

Each shard can process its own set of transactions in parallel with the others, allowing for a much larger overall transaction processing capacity. The "adaptive" aspect of adaptive state sharding refers to the ability for the network to automatically adjust the number and size of shards based on the current usage and demand, in order to optimize performance and maintain decentralization. This approach is used by MultiversX network as one of the features that allows it to reach high transaction throughput while also remaining decentralized and secure.

More details, here: https://docs.multiversx.com/technology/adaptive-state-sharding