An "ox" refers to a type of cattle that is specifically trained to do agricultural work. The plural of this term is "oxen." Usually oxen are male and have been castrated.
* Throughout the Bible, oxen are depicted as animals tied together by a yoke to pull a cart or a plow.
* Oxen working together under a yoke was such a common occurrence in the Bible that the phrase "to be under a yoke" became a metaphor for hard work and labor.
* A bull is also a male type of cattle, but it has not been castrated and has not been trained as a work animal.