Member Wait Events in Wait Classes

Today I will be sharing the member wait events present in wait event classes. By looking into the list one can conclude to which parent class the occurring events belong to and narrow down the investigation.
Oracle Wait Events are conditions where a session is waiting for something to happen.  A wait event can be caused by many things, from slow read/write speeds on the disk, to locking situations caused by the architecture, to various kinds of Oracle contentions.  Waits are either system-level or session-level.  A session-level wait event is an event that affects a single user activity within the database.  System-level wait events affect the entire database system.