This bug is valid and has recently been filed. Bugs in this state become IN_PROGRESS when somebody is working on them, or become resolved and marked RESOLVED.

The problem is a duplicate of an existing bug. When a bug is marked as a DUPLICATE, you will see which bug it is a duplicate of, next to the resolution

A fix for this bug is checked into the tree and tested.

This bug is not yet resolved, but is assigned to the proper person who is working on the bug. From here, bugs can be given to another person and become CONFIRMED, or resolved and become RESOLVED.

The problem described is not a bug.

The problem was specific to a related product whose bugs are tracked in another application

This word, or the terms "REQUIRED" or "SHALL", mean that the definition is an absolute requirement of the specification. RFC2119

This phrase, or the phrase "SHALL NOT", mean that the definition is an absolute prohibition of the specification. RFC2119