Since you sound genuinely curious, as far as what they can and can’t eat: First off the subtle nuances between Vegan and Vegetarian I can’t say I’m 100% knowledgeable of. I think Vegan is a little more strict and almost religious. Generally speaking they both can eat anything that doesn’t have animal parts of any kind. Some versions can eat products that don’t harm the animal like eggs and dairy. So yes generally speaking pastas, breads, grains, etc are all ok. They just have to get their protein from non animal sources which is actually very healthy because plant based proteins are considered better for you. A properly balanced vegetarian diet is generally considered healthier than a meat eating one. I think fish is the only meat that is probably as healthy. But to do it right you have to know what foods you need to be eating instead of meat.

I actually decided to get healthy a little over a year ago and have been eating salads every day for lunch. I used to be a proper meat eater and had to have a meat with pretty much all my meals. As my diet has evolved and my salads have become more complex and varied I’m more and more often not bothering to try and figure out some meat to take and eat with or in my salad. I also crave it less for dinner so I naturally eat less of it. Not sure if I’ll ever go full vegetarian though even though we have some in the family.