Can I say I am single after divorce?

As a single person, you are not legally bound to anyone—unless you have a dependent. You can be considered as single if you have never been married, were married but then divorced, or have lost your spouse. It is possible to be single at multiple times in your life.

Is divorced and single the same thing?

The difference between Divorced and Single. When used as adjectives, divorced means cut off, or separated, whereas single means not accompanied by anything else. Single is also verb with the meaning: to identify or select one member of a group from the others.

Do I have to select divorced as marital status?

The law itself only identifies people as Single or Married, not any other form. The government only cares about your current status and Divorced is not a current status; it is an identifier of the past - your history.