起重机是指在一定范围内垂直提升和水平搬运重物的多动作起重机械。又称天车，航吊，吊车。

轮胎起重机的主要特点是：其行驶驾驶室与起重操纵室合二为一、是由履带起重机（履带吊）演变而成，将行走机构的履带和行走支架部分变成有轮胎的底盘，克服了履带起重机（履带吊）履带板对路面造成破坏的缺点，属于物料搬运机械。

桥式起重机是横架于车间、仓库和料场上空进行物料吊运的起重设备。由于它的两端坐落在高大的水泥柱或者金属支架上，形状似桥。桥式起重机的桥架沿铺设在两侧高架上的轨道纵向运行，可以充分利用桥架下面的空间吊运物料，不受地面设备的阻碍。它是使用范围最广、数量最多的一种起重机械。

The crane refers to a multi-action lifting machine that can vertically lift and horizontally carry heavy objects within a certain range. Also known as crane, aerial crane and crane.

The main characteristics of the tire crane are: its driving cab and lifting cab are integrated, and it is evolved from the crawler crane (crawler crane). The crawler and walking bracket of the traveling mechanism are turned into a chassis with tires, which overcomes the defect of the crawler crane (crawler crane) crawler shoes causing damage to the road surface, and belongs to the material handling machinery.

The bridge crane is a lifting equipment that is transversely framed over the workshop, warehouse and stock yard to lift materials. Because its two ends are located on tall concrete columns or metal supports, it looks like a bridge. The bridge of the bridge crane runs longitudinally along the track laid on the overhead on both sides, which can make full use of the space under the bridge to lift materials without being hindered by ground equipment. It is the most widely used and the largest number of lifting machinery.