Invisalign is a clear aligner system used to gradually straighten teeth as an alternative to traditional braces, addressing various orthodontic issues such as overbite, underbite, and crowded teeth. It is suitable for most adults and teenagers with healthy teeth and gums, and treatment typically lasts around 12 months. The process involves wearing a series of customized aligners that are removable for eating and maintaining oral hygiene, offering comfort and discretion compared to conventional braces.