Dotted Notes and the Tie

Dotted note in music is a performance technique that indicates that a note should be played briefly and not connected to adjacent notes. The attachment point is usually represented by a small dot (·) placed to the right of the note. Its function is to create a brief interval within the duration of a note, making the performance of the note more intermittent and powerful.

Tie - is a mark in musical symbols used to connect two notes of the same pitch, playing them as a continuous note. The function of a hyphen is to extend the duration of a note, merging the lengths of two notes into one note.

Dotted note and tie are two types of markers used to change the duration of a note
Increase 1/2 duration of a dotted note
Since the duration of an eighth note is half that of a quarter note, we will use it instead of a half note
A dotted quarter note is equal to a quarter note plus an quaver note. A dotted quarter note can also be equal to three quaver note.
The tie combines multiple notes of the same pitch, and can be used to span the duration of a note across the bar line
The fourth and fifth notes have now been merged.
If there is no bar line, a half note can be used instead.
below can be used as reference