Rationalism and empiricism are two different schools of thought. The main difference between the two schools of thought is the relationship between experience and the creation of knowledge. Rationalists believe that knowledge is innate, and occurs prior to, or before experience. Rationalism tends to be skeptical of one's perception of the senses.
It holds that whatever we see, smell, taste, hear, and even feel are just opinions that are biased by experience; therefore, we cannot fully trust them as sources of truth so far our experiences are different. Empiricists, on the other hand, believe that knowledge can only occur to someone as a posteriori, which is after the experience.
Their belief is that humans start their life with “blank slate,” and they begin to fill that slate with knowledge as their experiences accumulate. A question asked by Empiricists is if knowledge is innate, why are children born without knowing everything?