Once you have your scanner or app ready, you need to tweak the scan settings to match your purpose. The main settings to consider are resolution, color mode, file format, and compression. Resolution is measured in dots per inch (DPI) and determines how sharp and detailed your scan is. Higher DPI means higher quality, but also larger file size and slower scanning. For web and social media, you don't need very high resolution, usually 72 to 150 DPI is enough. Color mode refers to whether your scan is in black and white, grayscale, or color. Black and white scans are the smallest and fastest, but may lose some details and contrast. Grayscale scans are slightly larger and slower, but preserve more shades and nuances. Color scans are the largest and slowest, but capture the full range of colors and tones. For web and social media, you may want to use color mode for photos and grayscale mode for documents. File format refers to how your scan is saved and encoded. Common formats are JPEG, PNG, PDF, and TIFF. JPEG is the most popular and compatible format, but it also compresses the image and reduces the quality. PNG is similar to JPEG, but preserves more quality and supports transparency. PDF is ideal for documents, as it preserves the layout and text. TIFF is the highest quality format, but it also creates very large files and is not widely supported. For web and social media, you may want to use JPEG or PNG for images and PDF for documents. Compression refers to how much your scan is reduced in size and quality to save space and bandwidth. Higher compression means smaller files and faster uploads, but also lower quality and more artifacts. Lower compression means larger files and slower uploads, but also higher quality and less distortion. For web and social media, you may want to use moderate compression, such as 80% or 90%, to balance quality and speed.