SPM Physics

In order to understand interference, u need to understand the concept of superposition.

The principle of superpositionstates that;

When two waves meet or overlap, the resultant displacement is equal to sum of the displacement of each wave.

Look at the figure below;

Check this video too..a creative illustration of wave superposition

the green wave meet the brown wave..yellow wave is produced

So... we can conclude that..interference will occur if two wavefront meets.

This will produce either constructive or destructive interference as shown in diagram above.

U should also check the following:

Water Interference

Light Intererence

Sound Interference