Rapidly developing technologies and new changes in modern dentistry have led to more effective solutions to be used in our clinical practice. The digital workflow includes some steps, such as data acquisition, digitalization, designing, and subsequently manufacturing by using digital devices. In this process, acquiring the images from patients' mouth, which is named computer-aided impression (CAI), is the first step of the digital workflow and named as digitalization. The need to skip many time-consuming intermediate steps and reduce the possibility of fabrication errors has made the digital workflow a popular choice for dentists and dental technicians. The popularity of intraoral scanners has increased rapidly since the 1980s. With the development of camera systems and software engineering, many companies have presented many different IOS devices, which are based on different software systems. This situation causes dentists to get confused due to the formation of a large data cluster. IOS devices are used to capture the digital data and they are an effective alternative to conventional impressions in many ways, such as increased patient comfort, time efficiency, hygiene, predictability, and precise results. Clinicians should have enough technical information about the IOS they use to obtain optimal results in fabricated restorations. The aim of this review is to evaluate the scanning technologies of intraoral scanners, their advantages, and disadvantages in clinical practice, scanning strategies, accuracy of scanning processes, and software protocols.