How do deductibles work?

So, I’m super dumb when it comes to all this insurance jargon, so I’m really confused here. I’m looking at getting insurance through my work and the best plan I’ve found is one that is $20 per paycheck (biweekly) with an annual deductible of $2,500. Does the $2500 deductible reset every year or what? Because $20 per biweekly paycheck would never cover that before the year is up. Can someone please help me understand this a little better. I only have 2 days before open enrollment is over with.