How is the social structure during the Renaissance different from the social structure of the Middle Ages?

The people of Renaissance Florence, like most city states of the era, were composed of four social classes: the nobles, the merchants, the tradesmen and the unskilled workers. The nobles lived on large estates outside the city walls. They owned most of the city's land, so the nobles controlled. The Middle Ages was an epoch in European history. While the Renaissance was a fervent intellectual and cultural movement. The Renaissance is described as the beginning of modernity. While the Middle Ages is described as a dark phase of European history.

less available tax revenue

this basically means that when they get money from taxes wirth having a lower gdp they get less then what others have with a higher gdp