What is Change Detection, how does Change Detection Mechanism work?

Change Detection is the process of synchronizing a model with a view. In Angular, the flow of information is unidirectional, even when using the ng Model to implement two-way binding, which is syntactic sugar on top of a unidirectional flow.

Change Detection Mechanism-moves only forward and never looks back, starting from the root (root) component to the last. This is the meaning of one-way data flow. The architecture of an Angular application is very simple — the tree of components. Each component points to a child, but the child does not point to a parent. One-way flow eliminates the need for a $digest loop.

There are two change detection strategies – Default and OnPush. If all components use the default strategy,

Zone checks the entire tree regardless of where the change occurred. To inform Angular that we will comply with the performance improvement conditions, we need to use the onpush change detection strategy.