basically, it is a virtual assistant (think of it like a little computer that sits on your fridge, or your table, or where ever you put it), and to activate it, you speak to it

for example: my one is alexa, so I'd say alexa, followed by what I want- so it can tell jokes, play games, tell you the time, the weather, play music, give you interesting facts, look up things on wikipedia, it's basically really smart (hence the name smart speaker. lol)

it's also great if you want it to wake you up in the morning, or remind you of a certain event coming up. it does everything!