(it should have a semi-colon on the end) is an entity for a non-breaking space.
Use it between two words that should not have a line break inserted between them by word wrapping.
There is a good explanation about when this is appropriate grammar on the English StackExchange.
It is sometimes abused to create horizontal space between content in web pages (since it will not collapse like multiple regular spaces). Padding and margins should usually be used instead of this hack.