c# code problem what does static mean

namespace functions
{
    class Program
    {
       static int maxval(int[] maximum)
        {
            int bigvalue = maximum[0];
            for (int i = 0; i < maximum.Length; i++)
            {
                if (bigvalue < maximum[i])
                {
                    bigvalue = maximum[i];
                }
            }
            return bigvalue;
        }
        static void Main(string[] args)
            {
                int[] myarray = { 10, 10, 8, 20, 93, 78 };
                int bigvalue = maxval(myarray);
                Console.WriteLine("The largest value is "+ bigvalue);
                Console.ReadKey();
            }

        }
       
    }

HTML:

When I remove the word static on line 5 before the function declaration and replace it with a acessor public or i just remove static completely I get an error

an object reference is required for the non static field required something something

what does static keyword do in C# why is it so important here do i need it in every function declaration

 

I hope this would help: http://msdn.microsoft.com/en-us/library/79b3xss3(VS.80).aspx

 

thank u ji abhi dekhtey hai