The words that join different ideas together are termed as conjunction. Therefore, a conjunction is a word that joins nouns or verbs or sentences.
AND - used for the words or sentences that are taken jointly. Conjunction ‘And’ shows addition and is used when the statements are similar.
Example: Ria and Sia are playing in the park.
BUT - used to show contrast in ideas
Example: Ravi is dull but Rohit is brilliant.
OR - used to indicate that only one possibility can be realized between the two
Example: Ravi or Mohan has done this.
BECAUSE - used to show reason of an action
Example: He did not go to school because he was ill.