L3 acquisition, also known as third language acquisition, refers to the process by which individuals learn a third language after already acquiring two other languages. This area of research examines the cognitive and linguistic mechanisms involved in learning a third language, as well as the factors that may influence the success or difficulty of this process. L3 acquisition research also explores how knowledge of previous languages may impact the acquisition of a third language and how individuals may transfer language knowledge between multiple languages. This area of study is important for understanding how multilingual individuals navigate and develop their language skills when learning additional languages.