The term "colons" can refer to two different things, depending on context.
1) In a sentence, a colon is a punctuation mark used to introduce a list or an explanation. For example: I have three favorite fruits: apples, bananas, and strawberries. Here, the word "colon" refers to the punctuation symbol ( : ) that separates the introductory phrase from the main clause of the sentence.
2) In a medical context, a colon is one of the large intestines located in the abdomen. It is responsible for absorbing water and electrolytes from the undigested food material and storing it as feces before eliminating it from the body through the rectum. Here, "colon" refers to the organ or part of the digestive system.