When I was trying to use foreach loop with classes or a value type I was doing it like that

foreach(int item in items)
{
   //rest of the code
}

However when I tried to loop the Dictionary like that

foreach(Dictionary item in dictionaryobject)
{
    //compile error
}

I got a compile error so I must use KeyValuePair

foreach(KeyValuePair item in dictionaryobject)
{
    //code
}

Why must I use KeyValuePair instead of the Dictionary?