A rough bulleted summary of each:
A typical Angel:
A typical VC:
VCs tend to invest other people's money (and more of it at any one time), but angels invest their own. Also, they have different motivations and different profiles. Angels aren't just in it for the money - they tend to want to be part of something successful, feel the thrill of being back in the game and have bragging rights with their mates (my investment is bigger than yours). Angels tend to be successful businessmen / entrepreneurs, but VCs have better hair.
VCs are professional investors, investing other peoples funds, expecting specific returns on their investment. Angels are private people with lots of money that believe in investing in small young companies.
The fact that VCs are professional means that they will add different elements to the term sheet (the contract under which they invest) that will not be in your favor, but they will have industry contacts that are very valuable, and raising money from them adds to your credibility, since they are trusted to invest only in things they believe will do exceptionally well.
If you need a seed stage investment (less then $1M) then an angel is what you need. VCs cannot invest small sums because they need to invest their funds in a limited number of companies (they don't have the manpower to handle many different investments). If your company is large enough to warrant a larger investment, and the growth potential is substantial, then you can give VCs a shot. Prepare well for the meeting, since they won't give you a second shot at it.