Something that's encouraging makes you feel better — more hopeful or confidant. A good theater director knows how to give her actors encouraging advice before they go on stage.
When someone you know needs extra help or support, a friendly letter or phone call can be encouraging, and if you're being treated for an illness, an encouraging word from your doctor will bring you a lot of relief. Encouraging test results are good ones — they deliver good news. The verb encourage is at the heart of encouraging, from the Old French encoragier, "make strong or hearten."