Albeniz’s Catalonian curranda

What is a curranda anyway? I know it came from the French courante but what are its characteristics? What makes it Catalonian?

The corranda, or correnta, is a popular sung dance (later also only instrumental) that is danced in pairs. It dates back to the 15th and 16th century. I do not know if it derives from the French couranté or if they arose at the same time. What makes it from Catalonia is that it is a typical dance of some areas of this region, especially around the Pyrenees mountain range.
Albéniz recreated, from a romantic and nationalistic point of view, something ancient.

How is it different from a gigue?

I can't tell you exactly.
The Giga is a fast dance in 6/8 usually.
The correnda, originally sung, is composed of four heptasyllabic lines with “square” rhyme (abba, abab, abcb).
I believe that many of these dances are, in their roots, related, and that they took different formats, and evolutions according to the geographical area.
The corranda has many names, depending on the area of Catalonia and the Valencian Country (further south): ball de córrer, remenadilla, cobla, cantarella, even follia.