The word port has several meanings:

1. A place where ships can dock safely to load and unload cargo or passengers. A port is like a parking lot for boats, usually in a harbor or bay protected from rough ocean waves. Major ports like New York, Singapore, and Rotterdam handle millions of shipping containers each year. Before airplanes, ports were the main gateways connecting countries and continents. When sailors say a ship is “in port,” they mean it's docked and resting rather than out at sea.
2. The left side of a ship or aircraft when you're facing forward. Sailors use port instead of “left” to avoid confusion, since port always means the same direction no matter which way you're facing. The opposite is starboard (the right side). Ships at night display a red light on the port side and a green light on the starboard side so other vessels can tell which direction they're heading. One way to remember: both port and left have four letters.
3. A place where something connects or plugs in. Your computer has USB ports where you plug in a mouse or keyboard. A charging port is where you connect a power cable. Like ships coming into port, information or electricity “docks” at these connection points.