Short answers, pulled from the story.
Synagogue derives from the Koine Greek word synagoge, meaning "assembly". The Hebrew equivalent, bet knesset, also means "house of assembly". Other names used by different communities include shul (Yiddish, from the Greek schola), kal (used by Sephardi and Romaniote Jews), and esnoga (used by Spanish and Portuguese Jews).
The earliest certain evidence for a synagogue is a stone dedication inscription from Lower Egypt dating to the second half of the third century BCE. Synagogues first emerged in the Jewish diaspora, probably after the Babylonian Exile of 586 BCE, and reached the Land of Israel several centuries later.
Every synagogue contains a bimah, the raised platform where the Torah is read, and a Torah Ark (Aron Kodesh in Ashkenazi practice, heikhal in Sephardic tradition) where the Torah scrolls are kept. A continually lit lamp called the ner tamid, the Eternal Light, is also a traditional feature, along with seating arranged so worshippers face toward Jerusalem.
The Great Beth Midrash Gur in Jerusalem is the largest synagogue in the world. Its main sanctuary seats up to 20,000 people, covers approximately 7,500 square meters, and the entire complex covers approximately 35,000 square meters. Construction took more than 25 years.
Samaritan synagogues face Mount Gerizim rather than Jerusalem. They use the Samaritan script, avoid depictions of humans, animals, and zodiac signs (which appear in some Byzantine-period Jewish synagogue mosaics), and continued building ritual baths next to synagogues after 70 CE, a practice Jews abandoned. The oldest known Samaritan synagogue is at Delos, with an inscription dated between 250 and 175 BCE.
The Paradesi Synagogue in Kochi, Kerala, India, built in 1568, is the oldest active synagogue in the Commonwealth of Nations. The Touro Synagogue in Newport, Rhode Island, built in 1759, is the oldest Jewish house of worship still standing in North America.