What this clause does
The residuary clause is the part of a will that says where everything not otherwise given should go. After the document pays creditors, taxes, and administrative costs, and after every specific gift has been satisfied, whatever remains is the residue. The residuary clause names who receives it and in what shares.
Practically, the residue is usually the largest part of an estate. Specific bequests tend to be small (a piece of jewelry, a vehicle, a charitable amount). The house, the investment accounts, and most of the wealth flow through the residuary clause.