COALESCE Ignore Parameter if it is null in SQL Server Queries or Stored Procedure

COALESCE Ignore Parameter if it is null in SQL Server Queries or Stored Procedure

Example :
SELECT Employee, City, DateHired
FROM Employees
WHERE Employee = COALESCE(@Employee, Employee)

If @Employee is null, it displays all the Employee details and if it is not null, it filters and displays the record.