Cheese spread is defined by what it does that block cheese cannot: it stays soft and scoopable straight from the tub, with no heat applied and no grating involved. This is processed cheese reformulated so it never sets. Cheese, an emulsifying salt, and a little water are blended until the result behaves like a thick, mild, slightly tangy paste rather than a solid, and it holds that texture cold, at room temperature, and under a knife. The whole identity sits in that one property. A cheese you can spread is a different proposition from a cheese you have to slice, and every use it gets follows from being scoopable.
The craft, from the point of view of the spread itself rather than any sandwich, is the emulsion. The emulsifying salt is what keeps the fat from weeping out and the protein from seizing into curd, so the spread stays smooth and homogeneous instead of splitting the way a melted hard cheese will. That stability is also why it is mild: the formulation trades the sharp, crystalline character of an aged cheese for something even, soft, and unthreatening, pitched deliberately at a young palate and a quick job. It needs no butter to carry it because the fat is already worked through it, and it spreads to the very edge of a slice without dragging or tearing the crumb, which is the entire reason it exists in a tub rather than a block.
The variations are a chiller shelf rather than a set of recipes. Plain is the baseline; versions carry chive, onion, garlic, or a stripe of something sharper worked into the same emulsion; the individually wrapped triangle and the squeezable tube are the same product in a different package. The made sandwich, the spread actually put between bread, is its own consideration and reads from the loaf rather than the tub. Each deserves its own article rather than being crowded in here.