A father is the male parent of an organism. It is often implied, however, to refer to human parents, unless otherwise stated.
The Bible states that one must honor thy mother and thy father, meaning that you must respect your parents.
It is also a term used for Roman Catholic priests. For example, if one's priest is named Henry, he would be referred to as "Father Henry." However, other religions, ex. Eastern Orthodoxy, often use this title for their pastors.