How to use articles in Spanish?

In general, there are two types of articles in Spanish - definite and indefinite.DEFINITE articles are the equivalents of English 'the' and are used to describe a very specific object. These are: EL (singular masculine) - el sol, LA (singular feminine) - la luna, LOS (plural masculine or mixed) - los compañeros, LAS (plural feminine) - las chicas.
INDEFINITE articles are the equivalents of a, an, and some and are used to describe a general concept, rather than a specific object.These are: UN (singular masculine), UNA (singular feminine), UNOS (plural masculine or mixed), UNAS (plural feminine).