If we want to tie a line off to an object we will likely use a hitch. A hitch can also result from tying a line back off to itself and some hitches enable the resulting work to be very taut, making hitches a valuable aspect of lashing down cargo, awnings, or loose items.
This is one of the best knots to tie when the need arises to tie a line to a pole. The direction of pull may be perpendicular or parallel if tied correct. It does not jam and weathers shocking loads well.
A very reliable knot for mooring and may be compared to the rolling hitch in application. The difference being this is a more secure knot to guard against shock loads, but the rolling hitch is better suited to an axial pull parallel to a spar. For permanent applications this may be seized, but you will rarely see this.
Actually a type of hitch, this is perhaps one of the very strongest, and has historically been used to to bend anchor cable to anchors, secured with a seizing. In construction it is very close to a round turn and two half hitches.
Used for tensioning rigging, the upper part is typically made off to a chain fall or come-along. This should not be used with cargo blocks, as the knot is intrinsically unsafe for those purposes. The double blackwall at least gives a better sense of security.
Mostly used for furling sails on square-riggers, this is a less seen knot today. It can be used for securing the end of a line to timbers, logs, or other devices, and easily shakes out when the strain is released. Coupled with a few half hitches along the shaft of a pole or spar, this can be used to lift those objects in rigging.
The barrel hitch (not to be confused with a barrel knot) is a method of raising or lowering a barrel, cask, or cylindrical object. There are several ways to tie this, but the simplest is to place the object on a length of line, bring the line up, wrap around hitching on either side, and tie with a bowline at the top.