The present real conditional's structure has two clauses. There is an adverb clause normally starting with If. There is also an independent clause.

Like all conditionals, the adverb (IF) clause has the condition, and the Independent clause contains the result.

In the present real conditional, The adverb clause is in the simple present tense, and the independent clause is in the simple present tense.

If I heat water to 100 degrees C., It boils.

If you hurt me, I feel pain.

Notice in the above examples the use of the simple present tense in the dependent (adverb) clauses, and the use of the simple present tense in the result clauses.

The clauses have been color coded. The independent clauses are in a different color while the adverb clauses are still in black.

Real means that if the condition is met, the result happens or will happen.

Unreal means that the condition will not be met, did not happen, or that it is very unlikely to happen.

When to use each kind of conditional

For generalities, you should use a present real conditional.

For plans that have requirements or possible setbacks, use a future real conditional.

For wishes, dreams, and speculation that is doubtful use a present/future unreal conditional.

For regrets, things you'd like to have done differently, and any past events you want to change (but you can't since you're still working on that time machine!) use a past unreal conditional.