Скачать или смотреть Image Size vs Canvas Size - What is the difference in Photoshop?

In Photoshop, there are two main options to change the size of your document – Image Size and Canvas Size. The difference between the two options can be confusing to beginners.

Canvas Size
By default, the height and width are constrained; if you change the height, the width adjusts automatically to maintain that ratio. In this way, the image is not stretched. However, adjusting an image to a larger size can result in the image becoming pixelated. By using this tool, you can make a picture smaller while keeping the scale, without affecting the image's borders as with canvas size.

Image Size
Your work area can be increased by using this feature. By default, all four sides of the current document are given extra space. Within the Canvas Size dialogue box, you can click on the arrows to adjust this. Canvas Size does not have fixed variables, which allows you to adjust it to your precise preference. If the layer is not locked, you can adjust the cropping by simply dragging the layer. For this reason, duplicate the background layer before changing the canvas size in order to prevent the layer from being locked.