Folic acid is the synthetic form of folate, an important B vitamin. Folic acid supplements help to prevent neural tube defects (NTD). NTD are congenital abnormalities that result in defects of the brain, vertebrae, or spine. We recommend starting folic acid supplementation before trying to conceive. You can take folic acid as a stand-alone supplement, or included in a prenatal vitamin. The recommended dose is generally 400-800 mcg per day, unless your provider tells you to take a higher dose (you may need a higher dose if you have a family history or a child with a NTD, or if you are taking certain seizure medications).
If given the choice between a supplement containing folate and folic acid, you may consider choosing the option with folate as it requires less processing by your body in order to use it. It should be noted however, there are not clinical studies to suggest improved outcomes from taking folate vs. folic acid, and the benefit is theoretical.