There are ten hindrances to enlightenment (shown below) and four stages of realization (enlightenment) based on how many hindrances have been eliminated and / or the degree to which they have been eliminated. A Buddha is someone who is fully enlightened. A person who is fully enlightened, but not the Buddha of our time, is called an Arahant in Pali. Such a person has eradicated all ten hindrances to enlightenment: (from Anguttara Nikaya 10.13)