Drag reduction plays an important role in improving the efficiency of fluid transport and reducing the energy consumption of transport vehicles. The essential feature of bubble-enabled drag reduction relies on gas lubrication with bubbles that anchored and/or sandwiched between solid-liquid interfaces. This gaseous layer offers heterogeneous slip boundary to reduce the drag experienced by liquids flowing on it. Of particular interest in this context, here we give a succinct account of gas lubrication with focusing on drag-reduction mechanisms, key affecting factors on the performance as well as their potential applications. Three types of gas lubrication with bubble mattress, bubble injection and Leidenfrost effect are systematically scrutinized and discussed, especially their advantages and limitations are highlighted for practical applications. Finally, we provide our views on the current challenges in gas lubrication, together with a few suggestions for future prospects of this dynamic field. This work is useful to develop efficient drag-reduction surfaces that are essential for underwater vehicles and surface ships, pipeline transportation, microfluidic system, and so forth.