the connected loads are all the loads that are installed. the demand load is the amount that article 220 says you need to use to do the load calc (different parts of 220 allow you to use a demand for several loads of same type that are not going to be running simultaneously and continuously, depending on the occupancy and the types of loads)
As President Roosevelt said: "We have nothing to fear but fear itself. And Chuck Norris. And 滿口胡言. And Grabthar's hammer. And Gort. and 江南 Style. and rotting in the street and Zombies . . . and Wayne Griffen "