A slot is a place where you can insert something, such as a coin in a machine or a paper into a printer. A slot can also refer to a position in a group, series or sequence, such as the job of chief copy editor.
A random number generator decides who wins and loses on a slot machine. When you press the spin button, a random number is generated in the exact moment that the machine is activated. If that number is the winning combination, then you get paid, but whether or not you win a lot depends on how many pay lines you bet on and which ones you land on.
Stack symbols allow normal symbols to take up more than one space on a reel, and increase the chances of forming a winning line. Some slots have stacked wild symbols, which act as additional wilds and replace other symbols to make the most valuable combinations possible.
If you want to play online slot games, you need to understand how they work. You can find out a lot by reading the pay table, which is the document that tells you what each symbol does and how to match them up for big wins. You can usually access a pay table by clicking an icon near the bottom of the game screen. Previously, these documents were printed on the machines, but now they’re embedded into the help screens of more complicated slots.