What happens in the concluding rite?
The very word "mass" comes from the concluding rite, in latin,
which the deacon says or sings, "Ite missa est..."
The concluding rite is a missioning rite (note, mission is also
from the same root as mass). Literally it is the part where we say,
"Go! You are sent!" like apostles.
It is the connection between the Eucharist and the world, the
blessing of the faithful who are now renewed in their communion to
go and be Christians in the world, to 'love and serve God and
neighbor' as the greatest commandment compels us to do.