If something experiences a revival, that means it’s once again popular or important. If a news story mentions a revival in the technology industry, that means the industry, having gone through a slump, is once again thriving.
Revival literally means "come back to life." An ER doctor might perform a revival of someone whose heart has stopped. We usually use it to mean "returned to glory, importance, or strength." Fresh paint and new flowerbeds might mean your neighborhood is experiencing a revival. If you don't like spiky hair, you may cringe at the revival of the mohawk in fashion magazines. Revival has a religious sense too, referring to a meeting that reawakens religious excitement and passion.