The word ‘vocation’ means ‘call’. God calls everyone to eternal life with Him. Before we get to eternal life, however, we have to live our earthly life. God has a different call for everybody in their earthly life. Following this call will enable us to gain eternal life. God’s call includes marital status, the type of work, and other activities. All calls to life are equally valid; there is nothing superior about the priestly or religious vocation (cf. Lumen gentium 40).
Most people are called to married life. A married couple, keeping the faith and bringing up their children in the faith, is what most people would expect to be doing. Within that family there could be various other activities, such as attending prayer groups, helping the homeless, etc.
Some are called to a life in the lay single state. This means living and working in lay society, without getting married. St Paul says that such people are free of anxieties about their spouses and can instead concentrate on serving God (1 Cor 7:32-39).
A few are called to the priesthood or religious life. Women can be called to active or contemplative religious life. Men can be called to priesthood, whether diocesan or as part of a religious community, or to religious life without priesthood. As with women’s religious orders, men’s orders can be contemplative or active, although there is not as clear a divide as there is with women’s orders.