Teacher development is a never-ending process that involves continuous learning, reflection, and improvement. It is important for both novice and highly experienced teachers. For novice teachers, development includes completing qualifications like CELTA and focusing on practical methodology and collaboration. For more experienced teachers, development involves doubt, reflection on practice, ongoing study, and pursuing additional qualifications. Effective teacher development combines practice, study, reflection, evaluation, and collaboration over the course of a teacher's career. It is important for developing subject matter expertise, pedagogical skills, self-awareness, and understanding of learners. Development can occur through personal study, getting learner feedback, peer observations, workshops, action research, and networking with other teachers.