And operator is "&&", or operator is "||". They are used in condition statements.
int i=15;
if (i % 3 == 0 && i % 5 == 0) {...}
if (i % 8 == 0 || i % 3 == 0) {...}
int i = 8;
int j = 9;
if (i % 2 == 0 || j % 3 ==0 ) //j % 3 == 0 is not checked, because i % 2 == 0 is true
{...}
int i = 8;
int j = 9;
if (i % 2 == 0 | j % 3 ==0 ) //j % 3 == 0 is checked, even i % 2 == 0 is true
{...}