delete vs truncate vs drop

The DROP statement is distinct from the DELETE and TRUNCATE statements, in that DELETE and TRUNCATE do not remove the table itself.
For example, a DELETE statement might delete some (or all) data from a table while leaving the table itself in the database,
whereas a DROP statement would remove the entire table from the database.

truncate cmd doesnt del the structure (metadata),it only deletes the data
drop deletes every thing i.e data+structure(metadata)

delete requires commit and rollback as it is DML
and unlike delete truncate is DDL and thus gets implicit commit;

drop and truncate are DDL(implicit commit)
delete is DML (requires explicit commit or rollback)