'Philodendron' refers to a large genus of plants belonging to the Family 'Araceae' - the same family as the Peace Lily.
There are 500 or so different species of Philodendron that are native to the Americas, with many varieties originating from Southern and Central America. They enjoy warm, humid environments such as rainforests, riverbanks and swamplands.
Philodendrons can vary greatly in terms of their appearance and characteristics. For instance, some have aerial roots that allow them to take nutrients from the air (rather than from soil), whereas others have typical subterranean roots that can grow notably long.
These plants can be divided into three different main types or groups, which are:
Epiphytes - these are plants that grow directly on top of other host plants, without having a detrimental effect on the host plant (i.e. they are not parasitic)
Hemiepiphytes - plants that spend part of their life cycle as epiphytes
Terrestrial Plants - 'normal' plants that grow on the ground
Philodendrons are quite easy-care plants, certainly when compared to other tropical rainforest plants, as they tend to be a bit less picky.
Exact care needs can vary depending on the particular variety of Philodendron that you have, but generally they like warmth and moisture. Try to provide them with partial sunlight - too much can damage their leaves, and too little can lead to leggy, sparse growth.
You may need to boost the humidity around your Philodendron by regularly misting and / or using a pebble tray.
The topmost layer of the soil can be allowed to dry out in between waterings, but ideally the soil should be kept somewhat moist at all times. Make sure it's not overly wet though, as this can lead to root rot.
Young plants have green leaves that get white stripes. Older plants get white leaves that develop green parts, how cool is that?!
Unfortunately, destruction of their natural rainforest habitat has left Philodendrons at risk of becoming extinct in the wild. Due to their popularity as a houseplant, though, they will at least stay living as cultivated species.
Philodendrons can also be utilized for their air-cleansing properties. Their large leaves are able to absorb toxins from the air, helping to purify your home.