A triangle with two diagonal lines inside or a triangle with CL inside and a cross-through indicates that you should use non-chlorine bleach. The circle is also important.

A square with a filled circle in the middle indicates 'tumble dry with no heat'. If the symbol has one line underneath, it means 'permanent press', and two lines mean 'delicate cycle'.

Depending on what is inside the water on the symbol, you'll need to wash your laundry at different temperatures and washing above the stated temperature (in Celsius) could damage your clothes.