Factorio Runtime DocsVersion 2.0.28

-- Both of these lines specify an item stack of one iron plate
{name="iron-plate"}
{name="iron-plate", count=1}

-- This is a stack of 47 copper plates
{name="copper-plate", count=47}

These are both full stacks of iron plates (for iron-plate, a full stack is 100 plates)
"iron-plate"
{name="iron-plate", count=100}