Usage limits are restrictions set by a service or application to control how much a user or system can interact with it within a specific timeframe. These limits help prevent abuse, control operational costs, and maintain service stability by capping the number of requests, data usage, or actions performed. In cybersecurity, usage limits play a vital role in defending against automated attacks, such as brute force or denial-of-service attempts, by ensuring that no single user or process can overwhelm system resources. Usage limits can be enforced per user, per IP address, or per API key, and may reset after a defined period (e.g., hourly or daily). Exceeding these limits typically results in temporary blocks or error messages.