solution
A file grouping several related projects so they can be opened and built together.
A solution (.slnx, or the older .sln) lists a set of projects and their build configurations; IDEs open solutions, and dotnet build on a solution builds every project in it.
Examples
dotnet new sln -n ShopwritesShop.slnx, anddotnet sln Shop.slnx add Tips/Tips.csprojputs a project in it.
See also