Generic values in ASP.NET

Question

Since I am new to working with C# asp.net 2010 within the last few fmonths, I have the following question to ask.
I have been using code like the following in my first *.aspx.cs program:
protected void methodname(object sender, EventArgs e)
{


}
I will haveen using this code since I have been alot of other methods being setup like this. However, can you tell me:
1. When should these type of paramters actually be passed to methods I am writing?
2. Do you know of a reference that would actually explain the generic and specific use of when to use (object sender, EventArgs e)?