answer: Zvi's link is perfect
Jewish answer: the worship of G-d and G-d alone. Studying His word in the Tanakh (which contains the Torah). Keeping His commandments (613 w/the Temple, 300 w/out the Temple). Caring for family, friends, community (which includes mandated charity). Working to repair the world (Tikkun olam) in preparation and anticipation of the Messiah/Messianic age.
afterlife
there are many views because the afterlife isn't described in Judaism. Most Jews don't focus on the afterlife, we let G-d worry about that. Jews focus on the here-and-now: keeping G-d's commandments, studying Torah, caring for others and helping to repair the world.
Some Jews believe that when someone dies and they are righteous, we go to join G-d immediately. If we aren't righteous they spend a short time away from G-d.
Some Jews believe that we enter a sleep-like state until the Messiah/Messianic age and then join in the new world to come.
Some Jews believe in reincarnation until the Messiah/Messianic age or until one becomes righteous enough to join G-d.
Jews do NOT believe in an eternal torment/hell. That would not be part of the righteous plan of a loving G-d. There is NO discussion or description of “hell” in the Jewish Tanakh. Some believe the utmost in evil souls simply cease to exist