Colons, semi-colons, and commas are all types of punctuation. Colons are dots that are centered on a vertical line. They are often followed by an explanation. An example of using a colon is Jane had three kids: Ann, Emily, and Bob. A semi-colon is used between independent clauses that are related, but not related enough to use a conjunction.
An example of using a semi-colon is Let's go to the kitchen; it is the only place that gives me a peace of mind. A common is used to create a pause in a sentence and can also be used to separate a list. An example is Larry went to the store for fruit, meat, and milk.