When a Prysm client is initialised out of the box, it starts a variety of services that run in parallel to handle everything required for the lifecycle of the beacon chain. In no particular order, Prysm includes:
A beacon node which powers the beacon chain at the core of Ethereum 2.0
A validator client connects to the beacon node and manages staking keypairs
A public RPC server to request data about network state, blocks, validators etc.
A P2P networking framework and server to connect with other beacon nodes
As described in this section, Ethereum 2.0 encompasses a distributed network of blockchains called shard chains which are coordinated by a root chain known as a beacon chain. This beacon chain serves as a mechanism to manage a set of Proof-of-Stake validators and overall consensus across shards.
Shards themselves are similar to the current Ethereum 1.0 chain, which stores blocks containing user-generated transactions such as token transfers and smart contracts. Ethereum 2.0 provides a massive improvement over 1.0 by having over 1000 of these shard chains, all with the capacity of the existing ETH1 network.
As shown above, the beacon chain runs through a distributed network of nodes known as beacon nodes. Participants who want to run a beacon node and help secure the network can stake 32 ETH to join a set of validators, which have the responsibility of proposing and attesting new blocks on the beacon chain. This deposit does not come out of nowhere however; validators transfer Ether from the ETH1 chain to the 2.0 system via a validator deposit contract.
Each of these components and their roles in the Prysm client are explained within the following sections of this documentation.