This exercise will help students to understand the concept of " Clipping Mask ".
What is Clipping Mask ?
Clipping Mask is a technique, in which a "Base Layer " is used to define visible boundary of an "Overlaying/Top Layer". 

Example
Photoshop Exercise #38 - Practice Clipping Mask Technique
Methods To Create Clipping Mask
Following are the methods to create clipping mask.

Method 1
  1. Place the the Clipping layer over the Base layer
  2. Right click on the Clipping layer in the layer panel.
  3. Click on "Create Clipping Mask" option. 
Method 2
  1. Use Short cut to Create clipping mask (Ctrl + Alt + G)
Method 3
  1. Place mouse pointer between the dividing line of Clipping and Base Layer in the layer panel.
  2. Hold "Alt" key.
  3. Press Left Click  
Methods To Release Clipping Mask
Following are the methods to release clipping mask.

Method 1
  1. Right click on the Clipping layer in the layer panel.
  2. Click on "Release Clipping Mask" option. 
Method 2
  1. Use Short cut to Create clipping mask (Ctrl + Alt + G)
Method 3
  1. Place mouse pointer between the dividing line of Clipping and Base Layer in the layer panel.
  2. Hold "Alt" key.
  3. Press Left Click  

EXCERCISES- Clipping Mask
Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique
Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique

Photoshop Exercise #38 - Practice Clipping Mask Technique 
Photoshop Exercise #38 - Practice Clipping Mask Technique