NuGet is the package manager for the Microsoft development platform including .NET. The NuGet client tools provide the ability to produce and consume packages. The NuGet Gallery is the central package repository used by all package authors and consumers.
In order to install a package, you can do it either through Nuget Package Manager UI
or through Package Manager Console using:
Install-Package PackageName -Project ProjectA
In case you want to install the same package on multiple projects, you can do it faster through the following command:
Get-Project ProjectA, Project | Install-Package PackageToInstall
For more info you can visit docs.nuget.org.