`ng-if`, `ng-show`, and `ng-hide` are directives in Angular that are used to control the visibility of HTML elements.
1. `ng-if`: `ng-if` is a structural directive that adds or removes an element from the DOM based on a condition. When the condition is `true`, the element is added to the DOM, and when the condition is `false`, the element is removed from the DOM. `ng-if` is used when you want to dynamically add or remove an element based on a condition.
2. `ng-show`: `ng-show` is an attribute directive that sets the `display` style of an element to `block` or `none` based on a condition. When the condition is `true`, the element is displayed, and when the condition is `false`, the element is hidden. `ng-show` is used when you want to dynamically show or hide an element based on a condition, but you want the element to still occupy space in the layout even when it's hidden.
3. `ng-hide`: `ng-hide` is an attribute directive that sets the `display` style of an element to `block` or `none` based on a condition. When the condition is `true`, the element is hidden, and when the condition is `false`, the element is displayed. `ng-hide` is used when you want to dynamically hide or show an element based on a condition, but you want the element to still occupy space in the layout even when it's hidden.
In summary, `ng-if` is used to dynamically add or remove an element from the DOM, `ng-show` is used to dynamically show or hide an element, and `ng-hide` is used to dynamically hide or show an element. The main difference between these directives is the way they control the visibility of elements and the effect they have on the layout of the page.