A furloughed employee has the expectation that employment can resume with the company, while a laid off employee does not. This is important for tax and other legal considerations.
This very much depends on where you are. For example in the UK a lay off technically means being told to stay at home because there isn't enough work [1], although it's often used these days to mean "fired without cause", i.e. the American usage of lay off has become more common and it has simultaneously became common to use the term "furlough" to describe layoffs during the pandemic.
