Most of today's washers, even the least expensive ones, have pre-wash soak and/or rinse cycles, detergent and bleach/dye dispensers, water temperature controls, water level controls for conserving water when washing small or medium loads, lint filters, and a series of washing cycle controls to vary the action of the agitator and the spin cycle.
An automatic washer basically does what you would do if you were going to wash clothes by hand, but it does it faster: clothes go in, water comes in and the clothes are washed, dirty water goes out, clean water comes in, clothes rinse, water goes out, and clothes come out.
When you set the selector switch and apply power, a double solenoid valve is activated. Water is allowed to flow in to the preset level, at which point the solenoids slam shut and cut off the inflow of water. (Many washers also have an overflow sensor or some system to handle an overflow of water if the solenoids fail to shut off the water.) Next the washing cycle is activated.
The agitator moves back and forth, and sometimes up and down as well, to clean the clothes. Agitator action is driven by a motor, a system of gears and/or belts, and a cam to create the reciprocal (back and forth) motion needed. Meanwhile, in most units a pump is used to recirculate and filter the wash water. The pump is activated and the wash water is drained from the tub.
To reduce the amount of water even more, the motor causes the tub to spin. The water is pulled out of the clothes by centrifugal force, leaving the clothes damp instead of soaking wet. During machine operation, short pauses occur as the washer moves from one cycle to another, or even in the middle of a particular wash or rinse cycle. These pauses are part of normal operation of a servo-mechanism inside the appliance as it changes from one mode to another.