do an image search with the terms "herpes" and another with the term "fever blister". They are two different sores. The oral herpes I have seen usually are a cluster of bumps on lips. The other kind of mouth sore you can get is called fever blisters, mouth ulcers, or canker sores. I get these when I accidently bite the inside of my lip. The cause is generally not known although many suspect it is from trauma or irritation from certain ingredients in toothpaste. You are not contagious. However oral herpes is caused by a virus and can be transmitted to another person. Once you have the the herpes virus, you have it for life. The viral strain is related to genital herpes but is different. i read that you can contract oral herpes in your genital region and genital herpes in your mouth region.