Connectives are used to make links between and within sentences, and they help writing to flow.
These sentences show the order in which things happen, and the connectives used are often referred to as sequencing connectives or time connectives.
I ate my breakfast. After that, I brushed my teeth.
Katie was out shopping for the afternoon. In the meantime, her mother cleaned the house.
If connectives are used to link clauses within the same sentence they are called conjunctions.
Joanna washed her hair before she went to the party.
Dwayne read a book while his brother played on the guitar.
Before, after, while, when and then are all sequencing conjunctions, but the words and phrases on the following list are not conjunctions but connecting adverbs and should be used to link sentences rather than join clauses within a sentence.
first
next
later
after that
before that
finally
eventually
in the meantime
meanwhile
Yolande spent a long time on her maths homework. Eventually she got it finished.
(Not: Yolande spent a long time on her maths homework eventually she got it finished.)