When something is continual, it is a frequent and repeated occurrence.

The phone rang continually throughout the day, interrupting my concentration.

When something is continuous, it is nonstop, without interruption.

Playing continuous white noise at night can help with falling and staying asleep.

Note: Be aware that although some writers make a distinction between continual and continuous, the two words are often considered synonyms and used as such. The one instance in which continuous, never continual, should be used is in the physical properties of something—for example, a continuous line.