Joe Biden signed a total of 19 executive orders during his first three days in office—more executive orders at the start of a term than any recent president. The orders related to environmental regulations, immigration and the ongoing COVID-19 pandemic, including a mask mandate on federal property, as well as orders related to economic relief, supplies and school reopening.
In his first 10 days in office, Donald Trump signed seven executive orders. In his first 10 days in office, Barack Obama signed five executive orders. George W. Bush only signed two, as did Bill Clinton.
Executive orders are directives from the president that do not require congressional approval. Congress can make it difficult to implement an order (for instance, by cutting off funding). Only a sitting president can overturn an existing executive order by issuing another.