There are two common types of Suspended chords: Suspended 2nd (sus2) and Suspended 4th (sus4). The Suspended 4th chord is the most common and is often referred to simply as a Suspended chord (sus). This creates confusion, and improper usage of the term Suspended is common, so if you run across a chord such as “Dsus” try a Dsus4 chord first, and if that doesn’t sound right try a Dsus2.