A semicolon can be used to join two clauses instead of a conjunction.
I love ice cream while my sister prefers jelly.
I love ice cream; my sister prefers jelly.
Both these sentences are correct, but using a semicolon adds variety to writing and makes it more interesting. In a way, the reader understands the word 'while' in the sentence even though it is not actually there.
Note that it is not correct to use a comma to join two clauses in this way. This is a very common mistake.
I love ice cream, my sister prefers jelly. (wrong)
A semicolon should only be used if the sections on both sides make sense in their own right. 'I love ice cream' and 'My sister prefers jelly' can both stand as independent sentences.
If the second part of the sentence adds information to the first part, but could not stand on its own as a sentence, then a colon should be used instead.
There is only one flavour of ice cream worth eating: strawberry.
Let's move on to some questions and practise using semicolons.