NameValueCollection is used to store data like Name, Value format. It is very similar to Vb.Net HashTable, HashTable also stores data in Key , value format . NameValueCollection can hold more than one value for a corresponding Key.

Imports System.Collections.Specialized

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, _

    ByVal e As System.EventArgs) Handles Button1.Click

        Dim markStatus As New NameValueCollection

        Dim key As String

        Dim values() As String
        markStatus.Add("Very High", "80")

        markStatus.Add("High", "60")

        markStatus.Add("medium", "50")

        markStatus.Add("Pass", "40")
        For Each key In markStatus.Keys

            values = markStatus.GetValues(key)

            For Each value As String In values

                MsgBox(key & " - " & value)

            Next value

        Next key
    End Sub

End Class

Adding new pairs

Add(ByVal name As String, ByVal value As String)

Add("High","80")

Get the value of corresponding Key

GetValues(ByVal name As String) As String()

String values() = GetValues("High")

When you execute this source code , you will get each Key/Value sets.