Slots are amongst the most popular games that casinos offer but, unlike poker, they're often seen as being an entirely solitary pursuit. That need not be the case, however. A social and competitive aspect comes into play with the tournament approach.
Typically a solo activity, tournaments make slots a more social event. In them, players compete against other gamblers playing the same slots game for the same amount of time. Whoever finishes with the best result is the winner of the grand prize.
As well as playing alongside others, you may have the option to chat to them too. This can be a nice way of fostering friendships or rivalry. Or you could be pretty quiet and focus on your game (after all, this is competitive gambling). If someone is being a bit obnoxious, just ignore them, as it's likely a ploy to try and put you off.
Some competitions are free to enter, which is a nice way to relax. The downside is the prizes, as you might expect, are a little weaker. You might win free spins at the casino, for example, or a small amount of cash. Other tournaments require a buy-in fee but this is often inexpensive. A side-effect of this buy-in is that gamblers know for certain how much they'll be spending (and hence their maximum loss) for the duration of the contest. The upside of these paid tournaments is that you win larger cash sums rather than free spins. Because the reward is based on the entry fees, the more players and the higher the fee, the larger the prizes. Of course, the more players there are, the lower the chance of anyone individual coming first, but that's just swings and roundabouts.
On that note, there isn't just one winner. There are usually a number of winning positions, so even if you're second, or third (or sometimes place quite a bit lower) you can win something back.
These are pretty basic, but worth mentioning anyway. Don't faff about, and keep your focus. You're there to win, and if you're distracted then you'll be both slower and not paying sufficient attention. Check to see if you can skip animations to save time.
The time frame can vary a lot, from half an hour to weeks. Likewise, the winning conditions can vary. It's often (especially for a short tournament) who wins the most, but sometimes, over a longer time period, it can be determined by winning streaks or other criteria. Select whatever time frame fits in best with you.
There's a wide range of different types of slots tournaments. Whether you want an hour of focused playing in a buy-in contest, or prefer a more relaxed free session, you should be able to find the format that suits your wallet, style, and available time.