The most frequent use of the semi-colon is between two complete sentences. It can be substituted for a comma plus a conjunction. Ex: Tom ate breakfast with his family, and then he left for his trip.

A dash is expressed as an "em dash" ( — ) in printing, is expressed in plain text as two hyphens ( -- ) and is used in place of a comma, colon or semicolon for greater emphasis. It denotes a major ...

(He wrote "Crisis Management by Apology: Corporate Response to Allegations of Wrongdoing.") A semicolon has two general uses: to clarify a series and to indicate two closely related sentences.