Exchanges only publish the total size resting at each price. When a price level's total rises above the threshold, a large order starts; when it falls below half the threshold or to zero, it ends. If the same level rises again later, that is a new order.
Thresholds: BTC ≥ 1M USD, ETH ≥ 500K USD, others ≥ 50K USD. Size = price × quantity, with USDT treated as USD. Only price levels within ±10% of the mid price are tracked.
A level below the threshold is hidden until it's back above it (its time on the book carries on); it ends once it falls below half the threshold, and we don't record whether it ended filled or cancelled. The exchange batches updates every 100 ms, so very brief orders may not show up.
Time resting counts from when we first saw the order; for orders far from price, or right after our collector restarts, it may have been placed earlier.
Source: Binance USD-M perpetuals, updated every second. Orders that have disappeared are not stored.

Binance USD-M perpetuals · every second Updated

BTC Large Orders