A berth is a designated location in a port or harbour used for mooring vessels when they are not at sea.
Locations in a port 
Berth is the term used in ports and harbors for a designated location where a vessel may be moored, usually for the purposes of loading and unloading. Berths are designated by the management of a facility (e.g., port authority, harbor master). Vessels are assigned to berths by these authorities.
Most berths are alongside a quay or a jetty (large ports) or a floating dock (small harbors and marinas). Berths are either general or specific to the types of vessel that use them. The size of the berths varies from 5-10m for a small boat in a marina to over 400m for the largest tankers.
Following is a list of berth types that can be found in a large port:
- Bulk berth: Used to handle bulk cargo. Vessels are loaded using either excavators and conveyor belts or pipelines. Storage facilities for the bulk cargo are often alongside the berth - e.g. silos or stockpiles.
- Container berth: Used to handle 20' and 40' standard intermodal containers. Vessels are loaded and unloaded by container cranes, designed specifically for the task. Alongside the quay there is often a large flat area used to store both the imported and exported containers.
- General berth: Used to handle smaller shipments of general cargo. Vessels using these would usually have their own lifting gear, but some ports will provide mobile cranes to do this.
- Lay berth: (Sometimes designated as "layberth") (1) A berth used for idle (lay-up  status) vessels. (2) A berth where no loading or unloading takes place. Lay berth and lay-by berth (below) may be used somewhat interchangeably for intermediate (two to seven day) periods.
- Lay-by berth: A general berth for use by vessels for short term waiting until a loading or discharging berth is available.
- Marina berth: Used to allow the owners of leisure craft on and off their boats. Generally alongside pontoons and accessed by hinged bridges (in tidal locations) to the shore.
- Product berth: Used to handle oil and gas related products, usually in liquid form. Vessels are loaded via loading arms containing the pipe lines. Storage facilities for the products are usually some distance away from the berth and connected by several pipes to ensure fast loading.
- X berth: Suitable for nuclear-powered warships, and part of an operational Naval base or a building and refitting yard
- Z berth: Suitable for nuclear-powered warships, as a location for operational visits or stand offs