Copla simply means stanza in Spanish. Usually when referring to the Copla as verse form, which appeared in the 14th century, it refers to couplets of irregular length with no fixed rhyme.

The Copla is:

1. stanzaic, written in any number of couplets.
2. syllabic, written in lines of irregular syllables most often ranging from 4 to 8 syllables.
3. rhymed at the discretion of the poet.
   
   
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Copla Real which became popular in the 15th century, is a decastich which is made up of 2 Quintillas.

The Copla Real is.

1. a decastich (10 line poem) made up of 2 Quintillas (Spanish 8 syllable lined quintains turned on only 2 rhymes of any combination other than never ending with a rhymed couplet.)
2. syllabic, all lines are 8 syllables.
3. rhymed, the rhyme scheme established in the first quintain is repeated in the 2nd quintilla. Possible rhyme schemes ababa, abbab, abaab, aabab, or aabba. The one no-no is it should not end in a rhyming couplet.