A online slot is a casino game that uses software to generate random sequences of numbers that determine where symbols land on the reels. Each spin of the virtual reels emulates the action of a physical slot machine, but it takes place in an instant, rather than over time as in a real machine. The result of a spin is determined by the combinations of symbols that land on each payline, and can be calculated using mathematical modules built into the game’s software.

All online slots use the same technology to create a fair and random outcome each and every time you press the spin button. This technology is called an RNG (random number generator). The RNG generates a new random sequence of numbers every millisecond. When you press the spin button, the random number is selected and compared to the existing values on the reels. The game then translates that number into an outcome for the current spin, which will ultimately determine your winning or losing chances.

There are a lot of misconceptions about online slot machines. Many people believe that the machine will take advantage of a player who leaves the slot to spin on autoplay for too long, or that it can cheat by awarding fewer wins. However, both of these things are simply untrue. Casinos and gambling regulators test the random number generators used in online slots to make sure they’re completely fair.

Another important factor to consider is the online slot’s volatility, which determines how often and how big you can expect to win. Slots are usually classed as low, medium, or high volatility. Low-volatility games will offer frequent small wins, while high-volatility machines may not pay out very often, but they’ll reward you with bigger wins when they do.