Complex carbohydrates and fiber (yes, fiber is technically a carbohydrate substance), like the carbs found in veggies, do wonderful things for your body like help fight chronic disease, and help keep you full and energized.
It's all about eating a plentiful amount of the healthful ones from plants (and less of those from added sugar or refined flours).
All vegetables have carbs but the content varies greatly, and is influenced by the water content of the plant. Leaves like lettuce and vegetables like cucumbers, are mostly water, and therefore low in carbohydrates. Tubers and root vegetables tend to be lower in water-content and higher in carbohydrates.
Starchy vegetables, like potatoes, sweet potatoes, parsnips, carrots, butternut squash, peas, corn (which is actually technically a grain) and beets. Legumes and beans, which are considered both vegetables and protein foods, are also high in carbs.