A slot is a narrow opening in something that allows for easy access. It could refer to the opening in a machine that you place coins into or it could also mean the space where a car seat belt slots in. The first is more common than the latter, but either way a slot is a small part of something that provides an easy entry and exit.
A video poker game that has more than one pay line is called a multi-line slot. These machines may accept 1, 3, 5, 7, or up to 1024 different symbols. They are similar to traditional mechanical slot machines, but they offer more ways to win.
Until recently in live casinos, players dropped coins into slot machines to activate games for each spin. This changed with the advent of bill validators and credit meters that allowed players to play without touching real money. Online slots allow players to advance deposits of credits from the beginning of their gaming session and most accept multiple forms of payment.
Air traffic management slots are the times that airlines have permission to operate at constrained airports. The allocation of slots is decided by EUROCONTROL and can be used for a number of purposes, such as allowing more flights to operate at busy airports, or to reduce fuel burn by keeping planes on the ground rather than in the air. They can also be used to manage the flow of passengers through a city or a region.