逐行扫描是一种在显示设备表示运动图像的方法，这种方法将每帧的所有像素同时显示。和逐行扫描对应的是隔行扫描，它常用于传统的电视系统中（逐行扫描有时候被称为非隔行扫描）。

逐行扫描常被用在计算机显示器上。通常的显示器的扫描方法都是从左到右从上到下，每秒钟扫描固定的帧数（称为帧率，例如60帧每秒）。

为了更细致的说明，我们来考虑一下标准电视机的扫描方式。通常电视机的扫描方式被称为隔行扫描，也就是说每一帧被分割为两场，每一场包含了一帧中所有的奇数扫描行或者偶数扫描行。通常是先扫描奇数行得到第一场，然后扫描偶数行得到第二场。

Progressive scanning (alternatively referred to as noninterlaced scanning) is a way of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video used in traditional analog television systems where only the odd lines, then the even lines of each frame (each image called a video field) are drawn alternately, so that only half the number of actual image frames are used to produce video.