This paper examines a number of features of online retailing and e-commerce, with a special focus on important topics including consumer behavior, multichannel marketing, and customer relationship management (CRM). According to existing research, online sales have several advantages for businesses, especially those with physical locations, such as better inventory control and increased profitability. The difficulties of integrating offline and online channels, maintaining consumer loyalty, and competing globally are all deeply analyzed. Small-business-specific CRM methods and innovative algorithms show improvements in client happiness and targeting. The study shows how e-commerce adoption and client loyalty are shaped by cultural variables, trust, and personalization. By covering the gaps in research on growing and regional markets, this review offers thorough insights into how online shopping is changing and how these changes affect retail tactics.