Hardtail

A hardtail refers to a frame that only has suspension on the front wheel. While bicycles typically have three suspension points, hardtail mountain bikes only have one. As a result, vibrations are transmitted more strongly than with full-suspension bicycles. However, there are certainly benefits to having only one suspension point: it's lightweight, rigid, and has a simple structure. In other words, opting for a hardtail makes it easier to achieve higher speeds and simplifies frame cleaning. Since mountain biking is mostly done in nature, having a simple structure that's easy to clean is likely a welcome advantage.