HTTP messages, often exchanged between a server and a client, form the basis of web communications, with webhooks being a specific type of HTTP request used in event-driven integrations. A webhook HTTP request typically consists of a start line, headers, and a body. The start line includes the method, URL, and version, with POST being the most common method used. Headers can be default or custom, providing essential information such as content type and authentication details. The body contains the data, often in JSON format, that is being communicated between systems. Webhooks are increasingly popular for SaaS integrations due to their flexibility and ease of implementation, making them a standard choice for data exchange in many modern applications.