Why were Egypt and Sumer considered civilizations?

Egypt and Sumer were considered civilizations because they developed complex societies characterized by urbanization, social stratification, and centralized governance. Both regions had advanced agricultural practices that supported large populations, alongside innovations such as writing systems (hieroglyphics in Egypt and cuneiform in Sumer) that facilitated record-keeping and communication. Additionally, they made significant advancements in technology, architecture, and trade, contributing to their status as foundational cultures in human history. Their rich cultural and religious practices further distinguished them as civilizations.