What exactly is petechiae and angiomas?

I have these little pin point red dots on my skin. They are raised a little and do not itch. I press on them and they don't fade, and they don't come and go. When I get one it seems to stay for good. I started getting them about 4 years ago when I was pregnant. And this morning noticed a few new ones on my thigh. Most of them are pin point, but I have one or two of them that are a little bigger, like the size of a pen dot, but they always start out as pin size.. I always assumed that they were angiomas, but today I just learned about petechiae. I have been trying to do some research about this, but pretty much every site says the same thing.
Does anybody know the difference between petechiae and angiomas?

[nalla]

Thanks for the responce! :)
Ok, with mine, they are raised bumps. Small, but when I touch them I can feel the bump. So that sounds more like angiomas right? I'm assuming when you mean the petechiae is flat, you can't feel it when you touch it, you just see it?
Is there any way to prevent angiomas from showing up?
Also, with mine, when I press on them, they don't fade in any way. Will a angiomas do that?

[chellybeans]

a petichiae is a form of bruising,it does not blanch when pressure is applied. it may or may not go away. they are flat. in essence they are broken pin point blood vessels. can be caused from illness, trauma or otther stresses to your skin like vomiting forcefully(around the eyes)

an angioma is a cluster of blood vessels near the surface of the skin. it grows larger, blanches when pressure is applied, and can be thicker as it grows. the reason it blanches is that the pressure cuts of the flow of blood to the vessels.

you can have laser treatment or electro cautery treatment of angiomas from most doctors but preferably a dermatologist.

[chellybeans]

no, sometimes they(angiomas) won't blanche. and yes, the petichiae are more like pin point bruises. small flat, no textural changes.  almost like someone poked you with a red ink pen.

you can't really prevent them, unfortunately it is a part of maturation.  at least ,to my knowledge. but you can get rid of them. typically that is considered a cosmetic procedure and out of pocket though :(

if you cut or nick one they will bleed a good bit. just apply pressure and a bandaid.