Blur ToolSharpen ToolBlur mode causes each pixel affected by the brush to be blended with neighbouring pixels, thereby increasing the similarity of pixels inside the brushstroke areaSharpen mode causes each pixel to become more different from its neighbours, it increases contrast inside the brushstroke area.Blurring can be useful to soften some element of the image that stands out too much.In “Sharpen” mode, the tool works by increasing the contrast where the brush is applied.