What is difference between static and singleton class?

Static classes are basically used when you want to store a single instance, data that should be accessed globally throughout your application. The class will be initialized at any time but mostly it is initialized lazily. Lazy initialization means it is initialized at the last possible moment of time. There is a disadvantage of using static classes. You never can change how it behaves after the class is decorated with the static keyword.Singleton class does not require you to use the static keyword everywhere. Static class objects cannot be passed as parameters to other methods whereas we can pass instances of a singleton as a parameter to another method.