Leggings are skin tight, usually cotton, 'pants'. They are more like thick stockings than pants. Most people wear long shirts or short dresses over leggings. Here is a picture of common leggings:
Jeggings are a legging/jean hybrid. They come in different forms! You can get jeggings that are literally as skin tight and soft as leggings, but just have a fake jean print on them. Or they have jeggings that are simply very stretchy and soft skinny jeans. They feel almost exactly the same as normal skinny jeans, just a tad more comfortable.
Skinny jeans/jeggings can basically be the same thing. Typically skinny jeans will be made out of a thicker fabric and be less flexible.
Attention: NOTHING on this site may be reproduced in any fashion whatsoever without explicit consent (in writing) of the owner of said material, unless otherwise stated on the page where the content originated. Search engines are free to index and cache our content. Users who post their account names or personal information in their questions have no expectation of privacy beyond that point for anything they disclose. Questions are otherwise considered anonymous to the general public.