Apparently the tiny seed of this flowering annual is one of the oldest oil seeds known to man. It hails from Africa and India originally but is now grown all around the world (see en.wikipedia.org).
Like a lot of cooking ingredients it tends to be a love or hate thing. Personally I love the nutty crunch they bring to my cooking, especially dishes from India, China and Southeast Asia. The extracted oil is one of my pantry staples.
By Krish Dulal – Own work, CC BY-SA 3.0,https://commons.wikimedia.org/
By Anna Frodesiak – Own work, CC0, https://commons.wikimedia.org/
Dietary Info: Great for vegetarians, vegans and is gluten free (as it is not a grass seed).
Here are more ingredients and posts about sesame seeds and oil: