The Articles of Confederation was before the United States Constitution and was very weak. Many people opposed the Articles, while many people were in favor of them.
With the Articles of Confederation, the government had little to no power. They could not tax citizens, regulate trade, or create and enforce laws properly. Over time, this ended up being a big problem and many thought it was weakening the country.
Anti-Federalists were in favor of the Articles of Confederation and did not want a new constitution. Many felt as if having a strong government would result in an abuse of power, like with what happened with Great Britain. They felt like the citizens should hold the power and the government should essentially leave them alone.
Federalists were in favor of a new constitution and did not want the Articles of Confederation. They felt as if having a weak government was harming the country and making it weak and having a strong federal government was a sign of a powerful and wealthy country.