The Collins and the Highball are rather similar glasses, with the only differing aspect being the slight shape change close to the bottom of the glass. This change in shape doesn’t necessarily alter the way the drink is enjoyed, so the two can be interchanged without affecting the cocktail.
Typically, the glasses are used for drinks built in the glass and served with ice and an effervescent component, such as tonic or soda water. The tall structure helps to retain the bubbles in the same way a Champagne flute works, and the size allows for both ice and mixer.
This type of glass is best used for a drink that is cold and refreshing over lots of ice, sometimes with garnishes and straws, such as a Gin Fizz or even the classic Gin and Tonic.