When you place money into a slot machine, it converts to credits. These credits can be worth anything from pennies to $100. Each individual credit has a different value, which is called the denomination. The denomination is displayed on the machine, usually in large letters and numbers. This is also how the machine is classified, such as penny or nickel machines.

When a player spins the reels, they must decide how much they want to bet per spin. This can be done by pressing a button or pulling a lever on older machines. The reels then rotate and stop randomly to display a combination of symbols. This combination will determine whether or not the player has won.

There are many different types of slots, ranging from three-reel mechanical models to five-reel video games. Some are themed after sports, television shows or other popular culture. Others are designed to be more interactive and offer bonus levels or other features that can increase the chance of winning.

In the early days of slot machines, there was often only one payline that ran horizontally through the center of the machine. More recent games have several pay lines that can run vertically, diagonally or in zigzag patterns. Some have multipliers that can multiply a win by a certain amount.

Most modern slots use a computer to control the outcome of each spin. The machines still look like the old mechanical ones, but they work on a completely different principle. Some of them even have a jackpot that increases over time, depending on the number of coins played.