MySQL slow query log consists of SQL statements that took more than long_query_time seconds to complete execution & required atleast min_examined_row_limit to be examined. By default, administrative queries & those that don’t use indexes for lookups are not logged.
MySQL replication allows you to ‘mirror’ databases on one or more servers(master) to one or more servers(slave). You can control what to replicate such as one or more databases, or even tables within a database i.e. selective replication.
MySQL binary log contains records of all changes to a databases—both data & structure—as well as how long each statement took to execute. It logs SQL statements such as CREATE, ALTER, INSERT, UPDATE & DELETE with the exception of SELECT & SHOW which have no effect on the data.