The main difference between crushed and diced tomatoes is the texture. Crushed tomatoes are, well, crushed, which means they're smoothed out and have a sauce-like consistency. Diced tomatoes, on the other hand, are chopped into small pieces, so they retain some of their texture and chunkiness. It might not seem like a big deal, but trust me, it can change the whole dynamics of your dish.
For example, if you're making a pasta sauce, you might want to use crushed tomatoes because they'll help create a smooth, velvety texture. But if you're making a fresh salsa, you'll want to use diced tomatoes because you want that chunky, fresh texture to shine through. It's all about balance and contrast, just like in music or art.
Crushed Tomato Vs Diced at Jack Dethridge blog
And let's not forget about the flavor! Crushed tomatoes have a more intense flavor because they're cooked down and concentrated, whereas diced tomatoes have a brighter, more acidic flavor because they're not cooked as much. So, if you're making a rich and hearty stew, crushed tomatoes might be the way to go, but if you're making a light and refreshing salad, diced tomatoes are the better choice.