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If you have historical data with timestamps and you want to predict how that data trends in the future, you can apply statistical methods yourself, or train a neutral net, or use an off-the-shelf package like Prophet.

Whether a layman finds it useful depends on the data, what they're used for, how well they're suited to Prophet's strengths, how lay the man is. I imagine by the time a layman gets to the point of understanding its strengths and weaknesses, she will no longer be quite a layman