Difference between == and .Equals method in c#

For Value Type:
== and .Equals() method usually compare two objects by value.

For Example:

int x = 20;

int y = 20;

Console.WriteLine( x == y);

Console.WriteLine(x.Equals(y));

Output:

True

True

For Reference Type:

== performs an identity comparison,
i.e. it will only return true
if both references point to the same object.
While Equals() method is expected to
perform a value comparison, i.e. it will
return true if the references point
to objects that are equivalent.

For Example:
StringBuilder s1 = new StringBuilder(“Yes”);

StringBuilder s2 = new StringBuilder(“Yes”);

Console.WriteLine(s1 == s2);

Console.WriteLine(s1.Equals(s2));

Output:

False

True

In above example, s1 and s2 are different objects hence “==” returns
false, but they are equivalent hence “Equals()”
method returns true. Remember there is an exception of this rule,
i.e. when you use “==” operator with string class it
compares value rather than identity.

When to use “==” operator and when to use “.Equals()” method?

For value comparison, with Value Type use “==” operator
and use “Equals()” method while performing value comparison
with Reference Type.