Here's my first new-cat owner question. What is safe for tick and flea prevention for an outdoor cat?

Is the monthly dab of gel considered non-toxic? What about the collars? My daughter’s cat is definitely going to be a long-term boarder here where the tick issues get more and more severe every year. Milo the Magnificent must be allowed out. My daughter will forgive me if a coyote or fox gets him, however. Confusing info on the web.