ASP. NET status: one sentence

Viewstate: page-level buffering. The page disappears when it disappears.

Session: Session-level buffer. It is created when a new page is opened, but the session is retained if it is redirected from one page to another. If a machine has multiple dialog windows, multiple sessions may exist.

COOKIE: Server-level buffer. A window opened on a machine shares a cookie. For example, if we log on once, you can open multiple windows in the future without logging on again.

Application: Server-level buffer. When multiple machines open the server page, the application obtained by each machine is the same. If one machine changes it, the value obtained by other machines also changes. However, application provides the lock and unlock mechanisms to prevent simultaneous modification.

Static variable: Server-level buffer, similar to application, but not locked