sql and or query-sql and or operators

As in have learnt about Where Clause with single condition. But there is not always single condition, most of the time we use multiple conditions while selecting data from table. For applying multiple conditions we use AND OR with Where clause.
The syntax is as:
SELECT * FROM table_name WHERE condition AND|OR condition
Now take an example of table employees
id first_name last_name salary city
1 Johan Sumith 200000 Delhi
2 Ansh Kumar 300000 Mumbai
3 Sameer Seth 100000 Delhi
4 Pyush 250000 Kolkata
Suppose we want to select those records in which either employee lives in Delhi or he has salary more than 250000.
SELECT * FROM employees WHERE city='Delhi' OR salary>250000
We get result as
id first_name last_name salary city
1 Johan Sumith 200000 Delhi
2 Ansh Kumar 300000 Mumbai
3 Sameer Seth 100000 Delhi
Now let us try another example with AND operator.
SELECT * FROM employees WHERE city='Delhi' AND salary>100000
The result is as:
id first_name last_name salary city
1 Johan Sumith 200000 Delhi