Error log: Problems encountered starting, running, or stopping mysqld
General query log: Established client connections and statements received from clients
Binary log: Statements that change data (also used for replication)
Relay log: Data changes received from a replication master server
Slow query log: Queries that took more than long_query_time seconds to execute
DDL log (metadata log): Metadata operations performed by DDL statements
fonte: https://dev.mysql.com/doc/refman/5.7/en/server-logs.html