The difference between Laundry and Washing

When used as nouns, laundry means a laundering, whereas washing means the action of the verb to wash.

check bellow for the other definitions of Laundry and Washing

Laundry as a noun:

A laundering; a washing.
Laundry as a noun:

A place or room where laundering is done - including, by extension, other forms of laundering than clothes washing.
Laundry as a noun:

That which needs to be, is being, or has been laundered.

Examples:

"You've left your dirty laundry all over the house."

Washing as a noun (countable):

The action of the verb to wash
Washing as a noun (uncountable, chiefly, British, NZ, Australia):

Clothing, bedlinen or soft furnishings that have been, are currently being, or are to be washed; laundry.
Washing as a noun (countable, often in the plural):

The residue after an ore, etc, has been washed
Washing as a noun:

The liquid used to wash an ore.
Washing as a noun:

A place where a precious metal found in gravel is separated from lighter material by washing.

Examples:

"the gold-washings, or silver-washings"
Washing as a noun:

A thin covering or coat.

Examples:

"a washing of silver"
Washing as a noun (stock exchange):

A fraudulent transaction in which the same stock is simultaneously bought and sold for the purpose of manipulating the market.
Washing as a noun (pottery):

The covering of a piece with an infusible powder, which prevents it from sticking to its supports, while receiving the glaze.