We have a lot of social networks. The thing is, it connects us with friends and family but most of the information on it is ephemeral. Legacy aims to let you share knowledge with your loved ones and grow together. It aims at aggregating content you find valuable and want to share with your kids, your brother, your best friends.
Think of it as a portal. On it, everything you love. The sum of your knowledge, your favorite books, essays, movies, podcasts, series, your thoughts about relationship, life, fitness, politics, the universe, religion, friends. Think of it as Wikipedia but created by you and your family, or you and your friends.