Practice and rehearsal are two words that are mostly used interchangeably, although they are not the same in their actual meaning. Practice refers to a repetition of an activity in order to ensure that such activity is well mastered.
When people want to improve themselves on a particular skill, they subject themselves to constant practice so that they can effectively master every aspect of it. With constant practice, perfection is usually the end result. On the other hand, rehearsal is a well-arranged form of practice that is conducted or performed before an audience in order to improve or test the interaction between all the participating people and to make a certain technical adjustment so that everything will be ready for the actual or real performance.
While errors and flaws are often overlooked when practicing, however, they must not be overlooked during a rehearsal. Practice will continually be done until one is good at it, while a rehearsal can be conducted in a day or few days.