Second Language Acquisition (SLA) refers to the process through which people learn a language other than their native one. This can occur in various contexts, such as in a classroom setting or through immersion in a community where the second language is spoken. Factors influencing SLA include age, motivation, exposure, and the methods used for learning. Research in SLA explores how learners develop skills in listening, speaking, reading, and writing. Theories such as Krashen's Input Hypothesis emphasize the importance of comprehensible input, while other approaches focus on the role of social interaction. Understanding SLA can help educators design effective language learning programs.