system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What does statistically significant mean?

If the p<0.05, what does this mean?!

For some reason I just cannot understand this concept.
gpt
It means "it's very unlikely this happened by chance".

Take a coin, and throw it into the air. It can either land heads or tails. If it's a fair coin, the probabilities are 50/50. Half the time it's going to be heads, half tails.

How likely are you to get heads twice in a row? 0.5 * 0.5 = 25%

How likely are you to get heads 3 times in a row? 0.5 * 0.5 * 0.5 = 12.5%

At some fuzzy point that's really quite arbitrary we just decide "Well, it's came up heads 100 times in a row. That's very, very unlikely to happen by chance, so it must be that the coin is rigged to fall on heads".

The "p < 0.05" is just a way to say "the probability of this happening by chance is below 5%", and somebody decided that a 5% risk of being wrong because things happened to align just right is acceptable.