What do you mean by ETag (Entity Tag) and how does it work?

1.	What do you mean by ETag (Entity Tag) and how does it work?
Answer» The ETag (entity tag) is a part of the HTTP protocol. This is one of several mechanisms that HTTP provides to validate Web caches, which allows conditional REQUESTS to be made from a browser to resources. Moreover, Etags make SURE that simultaneous updates of the same resource don't overwrite each other (mid-air collisions). ETags are opaque identifiers assigned by a server to a specific version of a resource FOUND at a specific URL. Every time the resource representation at that URL changes, an entirely new ETag is assigned. As such, ETags can be COMPARED in the same way as fingerprints and determine if two representations of a resource are identical. Syntax: ETag: W/"<etag_value>" ETag: "<etag_value>"

Answer»

The ETag (entity tag) is a part of the HTTP protocol. This is one of several mechanisms that HTTP provides to validate Web caches, which allows conditional REQUESTS to be made from a browser to resources. Moreover, Etags make SURE that simultaneous updates of the same resource don't overwrite each other (mid-air collisions).

ETags are opaque identifiers assigned by a server to a specific version of a resource FOUND at a specific URL. Every time the resource representation at that URL changes, an entirely new ETag is assigned. As such, ETags can be COMPARED in the same way as fingerprints and determine if two representations of a resource are identical.

Syntax:

ETag: W/"<etag_value>"

ETag: "<etag_value>"

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