Portrait Mode is used when you are taking a photo of a single object. You need to get close to your object so that it focus on it.

Manual Mode is used by mostly anyone who owns a camera uses this mode. It is the easiest mode to work with.

Landscape Mode is used to capture points of interest. The photos are taken at a wide angles,  from a distance.

Automatic Mode it pretty much does everything for you. Your camera chooses your ISO, it selects your shutter speed, aperture, and focus for you.

Night Mode is to shoot when their is low light. It captures detail in the background and uses a longer shutter speed.