With slots, though unpredictable, your actions do impact the result. If a deck of playing cards is set, the cards will not change based on your decisions. Unlike a deck of cards in an actual, physical casino, the exact time that you hit the spin button will play a role in determining what the result is. This means that each spin is as close to truly random as possible.
Just like Vegas slot machines, online slots use an RNG to generate results for each spin. You can access online slots from your desktop computer or mobile device. For the most part, online slots work the same way as the majority of slot machines that you will find in casinos around the world.