Social distancing and stay at home are two different concepts.
Social Distancing: Aims to reduce the number and closeness of interactions between people while allowing them to carry out their necessary day-to-day activities. Why? to reduce face-to-face contact and the spread of germs. If you have to go out in public, stay six feet away from others. Minimize close contact between you and other people.
Stay at home (shelter in place): People stay in their home unless they need to leave for essential activities and work. This is an order that can be legally enforced. Why? This has been done by some cities and states in order to slow the spread of the coronavirus by minimizing contacts between people. It bans all socializing and activities outside of the home. Essential businesses remain open, such as grocery stores and pharmacies. Residents can leave their home for activities such as walking their dog or seeking medical care, but must maintain social distancing.
Various govenors decided social distancing wasn't working and so ordered stay at home orders to be in effect. That is what happened in Virginia several days ago.