PLA is short for polylactic acid. It is currently the most popular and commonly used 3D printer filament in use due to it's ease of use and relatively inexpensive price.
PLA is derived from renewable resources, such as corn starch or sugar cane. This means it is biodegradable, therefore environmentally friendly.
It is available in a variety of colours, and other styles such as (but not limited to):
One of the more popular types of PLA is wood filament. Wood filament is actually a combination of PLA and real wood fibers (such as recycled materials from wood mills). This product has the feel of real wood and can be stained, painted, sanded or vanished. This product has the smell and feel of wood, and is lightweight compared to real wood.. It is used mainly for decorative products, however it can be abrasive on the printer's nozzle (0.5 mm nozzle is recommended).