ELI5: What's the fundamental difference between segregation and community?

This is a classic 'ELI5' (Explain Like I'm 5) type of question that touches on critical social concepts, often misunderstood or conflated. A content piece could clearly define both terms, illustrate their historical and contemporary applications, and explain the key distinctions in intent, power dynamics, and societal impact. It would be highly valuable for anyone grappling with social justice, community building, and the nuances of social organization, especially in a diverse society.