Resolution is a term that has multiple meanings. In this video I will focus on resolution in term of image.
Image resolution is the detail an image holds. Generally speaking, resolution is the sharpness and clarity of an image. Higher resolution means more image detail. The term is most often used to describe bit-mapped graphic images. The resolution is measured by the number of horizontal pixels and number of vertical pixels; for example, 640×480 (and it is written in this format). When resolution increases, images become blur due to a higher pixel density. In fact, text and images may become smaller because more pixels per-inch are being displayed. For example, going from just 800×600 to 1024×768 would increase the total number of pixels by 306,432.
In a nutshell, resolution is the quality of the image. As the resolution goes up, it becomes sharper, more defined, and more detailed as well. Because there are more dots to display the details of the images.