thx for the people who gave helpful infomrations for the last message, but what is a spider?  
sorry if the question is not smart, but i am a really true newbie

If you are talking about a person's skin appearance, spiders are visible veins that can be seen through the skin. Typically there are many of the small veins radiating through the skin like a spider's web. Very fair skinned people have more of a problem with this condition than darker people, although there are some cases where a darker person has a health condition that makes the veins highly visible.
There are also investment vehicles that are called spiders, but my guess is that you were not asking about those.

What's a spider?  It's an eight legged creature that often spins webs and sucks out the juices of it's prey.

In the context of the message you are referring to, a "spider" is "sarcasm."

Just so that I can be a smart-aleck too:
a spider is a software application that follows new links, meanders through the web, and converts everything into an unbelievably massive data file that can be searched on an engine such as google or yahoo.

It is also the Standard & Poor's 500 index tracking stock, known as SPDR (standard and poor's depository receipts). It is one spider that providers love to receive as gifts.