Off topic:What Does P<0.05 Mean?

Question

[Dole]

hi there

I'm new in the field, and I read some plos articles. I meet the term p<0.05, but I don't know what it means. Can you give me a keyword or something to help me understand what that p is about?

During the cranberry period, 6 subjects had 7 UTI, compared with 16 subjects and 21 UTI in the placebo period (P<0.05 for both number of subjects and incidence).