ngIf

The ngIf directive is used to include an element and its content in the HTML document if the expression evaluates as true.

Example
<div *ngIf="getCartSize() = 0">
  Your shopping cart is empty
</div>

ngFor

The ngFor directive is used to generate the same set of elements for each object in an array.

Example
<table>
  <tr><th>Name</th><th>Category</th><th>Price</th></tr>
  <tr *ngFor="let item of productList">
    <td>{{item.name}}</td>
    <td>{{item.category}}</td>
    <td>{{item.price}}</td>
  </tr>
</table>