Loneliness is a negative state of mind, marked by a sense of isolation. One feels empty and that something is missing. It is possible to be with people and still feel lonely (hope one does not have to go through that). Solitude is the state of being alone without being lonely. It is a positive and constructive state of engagement with oneself. It is desirable, a state of being alone where you provide yourself a wonderful and a sufficient company all by yourself. Where solitude restores body and mind, loneliness instead depletes them.
All tasks that involve deep thinking , one has to be in a state of solitude for the best understanding.
Travel through your own interior universe and that’s what is called SOLITUDE.