V$LOCK_TYPE describes the type of locks available.

Column Datatype Description
TYPE VARCHAR2(64) A two-letter internal resource identifier
NAME VARCHAR2(64) Resource type name. This is a short (less than 32 characters) enqueue type name.
ID1_TAG VARCHAR2(64) Description of the enqueue type.
ID2_TAG VARCHAR2(64) Further description of the enqueue type.
IS_USER VARCHAR2(3) User enqueue. These are enqueues that are acquired as a direct result of a SQL statement. Applications may get deadlocks on these enqueues. Such deadlocks are considered application errors.
DESCRIPTION VARCHAR2(4000) Explanation of how or for what purpose the enqueue is used.