Guitar slides are an inexpensive accessory that every guitarist should own. They are tubes worn on the finger of your fret hand, and when positioned correctly and moved along the length of the strings create a distinctive, fluid transition between notes.
Mostly associated with country and blues styles, the slide has a loose vibe and allows you to seamlessly blend notes along a curved line. Depending on the slide’s material, you can create different sounds - for example, a glass slide will bring out a warm, rich sound while a metal slide will react with your strings for a brighter sound with a little more attack.
Don't forget that slides come in different sizes, so make sure you pick one that suits your playing style the best. A shorter slide can be worn above the knuckle joint, allowing you to still bend your finger. That will help you with fretted chords or lead work, while full-finger slides are designed to accommodate the full width of your fretboard, great for playing full chords in an open tuning.