apollo-server-core
This package implements the core logic of Apollo Server. It exports a base version of ApolloServer. Typically you do not use this class directly but instead use an ApolloServer imported from the batteries-included apollo-server package or one of the integration packages like apollo-server-express.
It also exports a set of plugins such as ApolloServerPluginUsageReporting which you can provide to the plugins option to the ApolloServer constructor.