Final answer:
A tie connects two same-pitched notes to extend the note value, while a slur connects multiple notes to illustrate legato playing.
Step-by-step explanation:
A tie is an arc connecting two same-pitched notes to extend the note value, while a slur is an arc connecting two or more notes together to illustrate legato playing.
In music notation, a tie is used to indicate that the value of the first note is continued into the second note without any interruption. This means that the duration of the two notes is added together to determine the total duration. On the other hand, a slur is used to indicate that a group of notes should be played smoothly and connected, without any separation between them.