The parent is the intention; the child-orders are the execution. Blotters show parent quantity, filled quantity and remaining quantity, with an average-fill-price rolled up from every child.
Keeping the parent off-market is the point. Nobody can see that a 900,000-share seller exists, only the 2,000-share slices arriving on various venues.
Example: a parent of 900,000 shares generates perhaps 1,800 child orders of 500 across six venues over four hours. If the parent were displayed, order-book-imbalance readers and momentum algos would front-run the remaining size and the seller would pay for the advertisement.
Related: child-order, algorithmic-order, order-slicing