Data binding in Angular is the process of connecting the data in a component's class with the corresponding parts of its template. The goal of data binding is to keep the data and the user interface in sync, so that when the data changes, the user interface updates automatically, and vice versa.
Angular provides several different types of data binding, including:
1. Interpolation: This is the simplest form of data binding, where a component's property value is displayed in the template using double curly braces (`{{ }}`). For example, if a component has a property called `name`, you can display its value in the template using interpolation like this: `{{ name }}`.
2. Property Binding: Property binding is used to bind a component property to a property of an HTML element. This is achieved using square brackets (`[]`) in the template. For example, if you want to bind a component's `width` property to the `width` property of an HTML element, you would use property binding like this: `[width]="width"`.
3. Event Binding: Event binding is used to bind a component's method to an event of an HTML element. This is achieved using parentheses (`()`) in the template. For example, if you want to bind a component's `onClick()` method to the `click` event of an HTML button, you would use event binding like this: `(click)="onClick()"`.
4. Two-way Binding: Two-way binding is used to keep the data and the user interface in sync in both directions. This is achieved using the `ngModel` directive, which provides two-way data binding for form elements. For example, if you want to bind a component's `name` property to an input element, you would use two-way binding like this: `[(ngModel)]="name"`.
In summary, data binding in Angular is the process of connecting the data in a component's class with the corresponding parts of its template. Angular provides several different types of data binding, including interpolation, property binding, event binding, and two-way binding, which can be used to keep the data and the user interface in sync in different ways.