Why mobile phones have multiple rear cameras ?

What is the reason, that smartphones have more cameras on the back side ?

Are all that cameras being used at the same time, when taking the photo ?

New smartphones usually have two, three or more cameras on the rear side. All the cameras have a specific functionality, to create better photos or videos and improve the user experience.

For example on the back side of Samsung smartphone, there is:

• Main camera
• Telephoto camera
• Wide angle camera
• Depth camera

Sometimes the mutliple cameras can work together.