API rate limiting is a control mechanism used in e-commerce and web services to restrict the number of requests or calls that can be made to an Application Programming Interface (API) from a specific client or source within a defined time period. It sets limits on the frequency and volume of API requests to manage traffic and maintain the stability and security of the system.API rate limiting serves multiple purposes in e-commerce and online services. It prevents abusive or excessive usage of an API, protects against Distributed Denial of Service (DDoS) attacks, and ensures that server resources are allocated fairly among all users. Rate limits are typically defined in terms of requests per minute, hour, or day. E-commerce businesses implement API rate limiting to strike a balance between allowing legitimate API usage and safeguarding their systems from misuse, helping maintain a smooth and secure online environment.