What are the differences between canker sores and mouth herpes (herpetic gingivostomatitis inside mouth)?

Canker sores: Canker sores (aphthous ulcers) have no definitive cause. They are thought to be caused by stress, allergies, trauma, diet, etc. They are usually self-limiting, healing in 7-10 days, with no other symptoms other than topical pain. Herpetic gingivostomatitis is due to a viral infection (herpes simplex virus). It often presents with symptoms of fever, headache, malaise. It usually heals in 7-14 days.

Canker sores vs HSV: Canker sores (aphthous ulcers) are painful sores inside the mouth. No one knows what causes canker sores. Herpes simplex virus (HSV-1) typically causes cold sores. Cold sore blisters can occur in many different parts of the body but are most common on or around the lips and cheeks.