Parangs are basically a step up from a machete and the two blades blend into one another at the extremes. A heavy duty machete and light use parang are very similar. For example Newt Livesays RCM is a 3/16" fully flat ground 12" blade, it is a bit on the thick side for a machete, but on the light side for a Parang.
Anyway, traditional parangs meant for wood cutting are around 1/4" thick with a sabre convex grind about 3/4 - 4/5 of the blade width, there is no distinct edge bevel. There is also an additional convex grind that goes up towards the spine to increase penetration on deep cuts (soft vegetation). Basically the blade has teardropped shape.
They are usually forged from simple steels, medium carbon and low alloy. They are usually not quenched and tempered but just left to air cool. They are much softer than what is common discussion on the forums, but they have a much higher impact toughness and ductility.
They are sharpened usually once a week. This is a honing along the full primary grind to a highly polished edge using a fine hone. Over time the whole blade thins out and gets delegated to lighter use. The blade length for serious work is usually a minimum of two feet, but they do get slightly longer and vastly shorter for utility / hunting work, 12" or so for the latter.
-Cliff