A slot machine is an American word for it, and in America slot machines are purely random. In theory it is possible, if not unlikely, to win the jackpot five times in a row.

A fruit machine is a specifically British term, and those machines are not random at all. They specifically use psychological tricks to look random, but they are not. They are designed to take in a certain amount of money before paying out. If you know the machine well it will often give you a feature, hold, nudge, or gamble opportunity to win the jackpot first. If you keep messing that up, eventually the jackpot will simply drop in. But it will cost more money to get to that point than if you know how to exploit that specific machine earlier.

The trick with a British slot machine is to recognize when it ‘wants’ to pay out and take the opportunity it gives you. If you miss that chance you will have to spend a bunch more money to get another chance.

The thing with holds was specific to some machines in the 90s. If two symbols came in and then you were offered holds, if you held the two like symbols and spun you would lose. If you ignored the holds and let all three reels spin you would win.

Equally, there were other machines that if you held the same reels three times in a row (if it let you do that) on the third time you would win. But often it would only offer you the holds twice and then not let you hold a third time.

I’ve seen some fruit machine sites out there that talk about specific games. There is a definite advantage to learning the games, since it will help you win sooner than if you are completely ignorant of the game.