C # const & readonly

Const is a constant, readonly is read-only, and "blog Er" knows that :)
So what are their differences? My personal summary is as follows:
I. Assignment
1) The variable modified by const must be assigned an initial value during definition, and variable values cannot be changed at other locations;
2) variables modified by readonly can be assigned values during definition or in the constructor. Variable values cannot be changed in other positions.
Ii. Call
1) The variable modified by const needs to be called using the class name, just like a static member.
2) The variable modified by readonly must be called by an object.
III,Code
Example:
Public class constreadonly
{
// Public const string firstname; // Error: initialization is required when the const variable is defined.
Public const string lastname = "landpy ";
Public readonly string age = "0 ";
Public constreadonly ()
{
Age = "27 ";
}
Public void deal ()
{
// Age = "123 "; // Error: readonly can be assigned only when the constructor or definition is used.
// Lastname = "Peter "; // Error: the const value can only be assigned at definition.
String TMP = string. empty;
TMP = constreadonly. lastname;
// TMP = constreadonly. Age; // Error: variables modified by readonly can only be called by objects.
Constreadonly = new constreadonly ();
// TMP = constreadonly. lastname; // Error: the variable modified by const can only be called by Class Name
TMP = constreadonly. Age;
}
}