Key Differences Between Modern Democracy and Greek City-State Democracy:

Representation:
- In modern democracy, representatives are elected by the people to make decisions on their behalf, while in Greek city-states, citizens directly participated in decision-making.

Scale:
- Modern democracies encompass much larger populations and territories compared to the Greek city-states, which were small and limited in size.

Equality:
- Modern democracies strive for equality among all citizens, regardless of social status or wealth, whereas Greek city-state democracies often excluded women, slaves, and non-citizens from participating in the political process.

Institutions:
- Modern democracies have a system of checks and balances, separation of powers, and independent judiciaries to prevent the concentration of power, whereas Greek city-states did not have such institutional frameworks.

Communication:
- In modern democracies, communication and decision-making processes are facilitated by technology such as the internet and social media, whereas in Greek city-states, decisions were made through direct assemblies and debates.

Political Parties:
- Modern democracies have political parties that represent different ideologies and compete for power, whereas Greek city-states did not have formal political parties as we see today.
Overall, while the basic principles of democracy such as rule by the people and protection of individual rights remain consistent, the practice and implementation of democracy have evolved significantly over time.