What does the traditional mode Legato mean?

Legato symbol is a line that connects the first sound and the last sound of Legato in an arc.

Legato means continuity, that is, at one go.

Like singing. If staccato means singing one note at a time, Legato means singing multiple notes at a time.

Generally, when singing, you sing a lot of words in one breath, and then sing the next sentence in one breath. The notes in this line of legato need a sense of sentence like singing.

However, in most cases, disconnected notes will be played in Legato. Connection means emphasizing tone and sentence sense.