Lightning talks are designed to be short presentations between five and ten minutes long, but are usually capped at five minutes. Most conferences will allot a segment of roughly 30 to 90 minutes long to speakers. Talks are arranged one after the other during the sessions.
Short speaking engagements are intended to be brief presentations that last anywhere from five to ten minutes, usually no longer than five minutes. Conferences typically assign a block of time, ranging from thirty minutes to an hour and a half, for speakers to deliver their talks in succession.