Display Suite is a contributed module that gives site builders more control over how content is displayed without writing custom templates. It provides preset layouts and lets you assign fields to specific regions through the admin interface.
Before Layout Builder existed in core, Display Suite was the go to solution for flexible content layouts. It is still widely used on legacy sites and remains actively maintained.
For new projects, Layout Builder is usually the better choice because it is in core and has a richer editor experience. However, Display Suite still has strengths, particularly its simplicity and its approach of working at the view mode level. Some developers prefer it because it feels more predictable than Layout Builder in certain scenarios. Both tools can coexist on the same site.