Yes, it's very, very easy to transmit. Sharing utensils, sharing drinking glasses, sharing towels, even just mouth-hand-hand-mouth transmission. (As in, someone who has it touches their mouth, then later touches someone's hand, and that second person touches their own mouth, which kids do a lot.)
I thought that an acquaintance who had shared food with my daughter had herpes simplex, and was very anxious for a while after (this happened a while ago now and my daughter is fine). Did a lot of research then and found how very easy it is to transmit (and how many people have it even without symptoms). It turned out that this person had herpes zoster (the chickenpox/ shingles virus) which is less and differently contagious.
If the person has shingles, it's contagious when it's a sore but the person who "gets" it gets chicken pox, not shingles. Then once you have chicken pox, there is always the possibility that the virus will result in shingles at some point, especially as you get older.
There is a new, fairly effective (~50%) vaccine against shingles though.
The one thing I never figured out in my research is what happens when someone who has been vaccinated
for chicken pox (but hasn't had it) is exposed to active shingles. Is the vaccine strong enough that it's the same as if the person already had chicken pox, and they can't catch it? It seems like it, if exposure = chicken pox and the vaccine is protective against chicken pox.