Hidden fields are a standard HTML functionality that requires no complex programming logic. Hidden fields have widespread support for most internet browsers. Since a hidden field is persisted and read from the Razor view page, no server resources are required.
ASP.NET Core 3 allows us to use hidden fields. Whatever you place in a hidden field will always be sent with the input data from other HTML elements in the form of a submission. This will be sent from where they were defined.
You can use Hidden Field to keep data on a .cshtml page and detect when data that's been stored in the hidden field has changed between postbacks.
It is recommended that you don't use a hidden field to keep sensitive data since the data can easily be revealed by right-clicking a web page and selecting View Page Source.