Education and teaching is an abstract subject and symbol occupies an important position. Computer technology holds promise for improving student achievement and teacher quality in educational programmes at all levels. Computer assisted instruction is an effective method for teaching visually oriented subjects such as ultrasonography. Teaching objectives should be carefully defined and resources for development identified. Education has always been important but perhaps never more so in man's history than today. It also reviews general learning issues such as learning styles and strategies, learner autonomy and the factors that affect the efficiency of the learning process. CAI is a supplementary instructional strategy in effective teaching. In this research paper mainly focused on uses of computers in education system and importance of computers in teaching and education life. CAI is that in which teacher use computers at different times and spaces according to the characteristics of the subject matter, the students and the available software and hardware.