An Explanation on the Difference Between a "Rolling 'R'" and a "Regular 'R'"

The technical term for a "rolling 'r'" sound is an "alveolar trill."

The technical term for a "regular" anglophone 'r' sound is "alveolar approximant." This is the 'r' sound used 99.9% of the time by anglophones.

Listen to the difference between these two sounds:

• ✗ Alveolar Trill; versus
• ✓ Alveolar Approximant

 Courtesy Wikipedia