泛型老是看不懂啊，谁帮我解释解释，通俗一点哦

using System;

//简单的泛型例子，泛型方法示例
namespace FanXin
{
class Program
{
static void Main(string[] args)
{

int[] col = new int[] { 1, 2, 3, 4, 5 };
int b =6;
//调用泛型方法
Console.WriteLine(Fan.Find<int>(col, b));
Console.WriteLine(Fan.Find<string>(new string[] { "a", "b", "c", "d", "e" }, "c"));
Console.WriteLine(Fan.Find<char>(new char[]{'a','b','c','d','y','m','h','s'},'d'));
Console.ReadLine();
}
}
public class Fan
{//非泛型类
public static int Find<T>(T[] items,T item)
{//泛型方法，如果查找到数据则返回位置，否则返回-1
for(int index=0;index<items.Length;index++)
{