An ETag (Entity Tag) is an HTTP response header that identifies a version of a resource. This allow efficient caching by providing the client a method to check for a new version before downloading. In general, the ETag is based on the file’s last modification time and size and usually handled by the reverse-proxy. This is called the weak ETag/ weak validation. Alternative, there is a strong or content-based Etag that hashes the resources and provides a new version with every change. In most...
