The long-handled tool with bristles that artists use for dabbing color onto canvas is a paintbrush. If you want to tint your walls in shades of pink, you'll also need a paintbrush.
Although some painters have famously splattered, dripped, rolled, and otherwise creatively applied paint to a canvas, the vast majority of them use paintbrushes. The type of paintbrush a housepainter uses has a shorter handle and wider bristles, but its purpose is the same: to smoothly and precisely apply paint to a surface. Whether your medium is watercolors, oil paints, or deck stain, your paintbrush will have soft bristles and a wooden or plastic handle.