Touring boards can be used for multiple purposes but are primarily intended for long distance paddling and expeditions. Generally, touring boards are built to sustain added weight that comes with hauling gear and have multiple attachment points on the board to hold down and secure that gear. Touring paddle boards are usually 28 inches and wider with anything less being more geared for racing.
As a standard, the narrower the board the faster it will go but the less gear it will be able to hold. The wider the board the more stable it will be. So, if you’re primarily using the board for a long, off-the-grid expedition you would want to choose a board with more width, around 30 inches+. If you’re going out for the day and want to explore and won’t need too much extra gear a narrower board might be the better option.