The order book consists of two halves: buy orders (bids) are arranged from top to bottom in descending price order, sell orders (asks) in ascending order. The best buy price and best sell price form the boundaries between which the spread lies.
The order book shows not only price but also market depth—how many securities can be bought or sold without moving the price. If small volumes are placed at nearby levels, a large order will be executed at progressively worse prices, "consuming" the book upward or downward.
For securities with low liquidity, which are common in the Uzbek market, the order book can be sparse: wide spread and isolated orders. In such situations, market orders are risky—execution price may be significantly worse than the last trade. Practical rule: the less frequently a security trades, the more important it is to use a limit order with a pre-set price.