Nested Query or Joins

I have heard joins should be preferred over nested queries. Is it true in general? Or there might be scenarios where one would be faster than other:

for e.g. which is more efficient way to write a query?:

Select emp.salary 
from employee emp    
where emp.id = (select s.id from sap s where s.id = 111)

OR

Select emp.salary     
from employee emp   
INNER JOIN sap s ON emp.id = s.id   
WHERE s.id = 111