system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The difference between Parliamentary Republics, Presidential Republics, Federalist Republics, and Presidential Democracies?
gpt
**Parliamentary Republic**:  The executive branch gets it's power directly from the legislature(or parliament). Normally the party that wins the most seats gets the prime minister but sometimes there are coalitions governments. "The Head of State" is normally a ceremonial, sometimes a monarch or a "president" with no major powers. 

 EX: UK Theresa May prime minister of the UK is a member of the legislature and is voted by the other members for the post.  If the USA had a parliamentary republic either Mitch McConnel(Senate majority leader) or Paul Ryan(Speaker of the House) would be the head of the executive branch.

**Presidential Republic**: The head of the executive branch also the head of state , is separate from the legislative branch.  The president is normally elected by the people in a nationwide election. While most legislative and executive branches have some checks and balances on one another, the two aren't the one in the same like with parliamentary systems. 

EX: The USA is a full presidential republic along with most of North and South America.  If the UK was a presidential republic, the head the executive branch would need to be elected. 

**Federalist Republics**: A Republic that gives provinces and other individual areas limited powers. One can be a federalist republic and a parliamentary of presidential at the same time.  EX USA is both federal and Presidental republic while India is parliamentary and federal.

**Presidential democracies**: Used interchangeably with Presidential Republics.