Both put a question to the community. The difference is who sees the answers: a poll's results publish to everyone when it closes; a survey's answers go only to the author.
Polls
One question, 2–6 answer options the author writes, and a required closing date. Voting takes an account; each person gets one vote and can change it until the poll closes. While voting is open, voters see the participation total — the author sees live counts privately. At the end of the closing day (the author's timezone), full results — counts and percentages — publish to everyone automatically. Once votes exist, the question and options are frozen, so the question people answered stays the question on record.
Surveys
Up to ten questions: multiple choice, yes/no, a 1–5 rating, or short text. One submission per person, editable until the survey closes (a closing date is optional here). Answers go to the author alone — readers see a response count, never anyone's answers. The author gets aggregate results for choice, yes/no, and rating questions, an anonymized list of text answers, and a CSV export.
Where to create them
Polls publish from the poll form, surveys from the survey form. Both are Premium membership features, and each published poll or survey counts toward the monthly piece allowance like any other content type.