The differences between these items is huge. Real cheese is made from milk, rennet, and salt.
Pasteurized process cheese can be made from a single cheese (solid, or powdered), or a blend of several cheeses. Cream, milkfat, water, salt, artificial color, oils (for consistency and texture), and spices may also be added. The mixture is heated with an emulsifier, poured into a mold, and allowed to cool. Think about that, powdered cheese, that does not even sound good. And when it comes to color, Cheddar is not glow in the dark orange, that is loads of artificial colors. Neither powdered cheese or the colors used can be good.
Many processed cheeses cannot even be labeled cheese in most countries.
This photo shows the import from New Zealand, Mainland Real Cheese, this is their Mild Cheddar, aged 18 months. This is 185 Baht/250 gram block, you just need a knife to slice it. This cheese has 3 ingredients, milk, rennet, and salt. I use this to make grilled cheese sandwiches, sauces, etc.
Mainland makes many types that are widely available in Thailand, such as Cheddar, Extra Sharp Cheddar, Edam, Swiss, and Epicure. When you read through the recipes that involve cheese, this is my go to cheese!
Any glance at a cheese display in Thailand will show processed cheese slices. For lack of better words, it is plastic, nothing more. Most contain more oil than milk.
When cooking, using a real cheese will really turn your recipe from ok, to excellent.