What is the term for sliding from one note to another, encompassing all notes in between?

The correct term for sliding from one note to another, encompassing all the pitches in between, is indeed glissando. A glissando creates a smooth transition that captures all the intermediate pitches, often used in both vocal and instrumental music to add expressiveness. This technique can be executed on various instruments, such as a piano or a sliding instrument like a trombone, and is frequently employed in jazz and contemporary music to create effects that convey emotion or fluidity.

Legato refers to a style of playing that connects notes smoothly without noticeable breaks but does not specifically involve sliding between notes. Portamento, while similar to glissando, typically refers to a more controlled slide between two specific pitches, often with a more gradual transition than a full glissando. Staccato describes a style of playing notes in a detached and separated manner, opposite to the fluidity of a glissando. Thus, glissando is specifically defined by the inclusion of all the intermediate notes in the slide, making it the accurate choice for this question.