A girth hitch is a fast way to connect a loop of rope (or webbing) to another object. Girth hitches are commonly used to connect a runner of webbing to a pole or tree.
See the discussion in the girth hitch example anchor for a reminder to not have the girth hitch "pull back" on itself.
You can also tie a girth hitch by slipping it onto the end of an object.
The "critical point test" (aka "scissors test") requires that if any one item fails, nobody should be injured.
A "bend" is a knot that joins two ropes.
A "hitch" is a type of knot that must be tied around another object.
The "whistle test" requires that if all rescuers let go, nobody should be injured.