How does the change tracking mechanism work in Entity Framework?

The Change Tracking mechanism in Entity Framework allows automatic recording of changes in entity objects loaded into the context (DbContext). When you load an entity, EF saves its original state. When calling SaveChanges(), EF compares the current state of the entity with the original and generates the appropriate SQL queries (INSERT, UPDATE, DELETE) to synchronize with the database.

Tracking is performed through an internal state tracker (Change Tracker), which stores information about the state of each entity: Added, Modified, Deleted, Unchanged.

Example:

using(var context = new MyDbContext())
{
    var user = context.Users.Find(1); // Load entity
    user.Name = "New Name"; // Change property
    context.SaveChanges(); // EF will detect that user has changed and perform UPDATE
}