Broadly defined, the term "commercial real estate" can be used to refer to any dealing with real property in a business context. It could involve leasing out office space, owning an apartment complex or selling real property along with and as part of the sale of a business. It might be industrial or agricultural property.
It could even involve residential properties like apartment complexes or rental houses being held for business or income-producing purposes. It can even involve working with the government.
Unless the property is a residence where the homeowner is living, you're probably dealing with commercial real estate.