Check out example codes for "List C# add from List". It will help you in understanding the concepts better.

Code Example 1

var list = new List<string>();
list.Add("Hello");

Code Example 2

//Declaring that its a list
List<string> test = new List<string>(); 
test.Add("Hello")

Code Example 3

List<string> initialList = new List<string>();
// Put whatever you want in the initial list
List<string> listToAdd = new List<string>();
// Put whatever you want in the second list
initialList.AddRange(listToAdd);

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