The spider web is made of different type of spider silk. Spiders can generate different type of silk to build different parts of their webs.
Bridge thread Bridge thread is constructed by very strong spider silk. Usually came back and forwards along the bridge thread, to lay more silk on it to make it stronger. Bridge thread support the weight of the whole web.
Anchor thread The spider carefully select the Anchor point and lay the anchor thread. Anchor thread is also constructed by strong silk, but usually it is only one single thread.
Frame thread Frame thread is attached on both sides on Anchor thread. Together with the Anchor thread, they form the outside frame of the spider web. Frame thread is constructed by less strong silk, and is only one single thread.
Radius Radius is the silk connect from web central to the frame. The silk used to make the frames and radius are not sticky. They serve for supporting purpose. The spider will walk on those radius and not be entangled by its own silk.
Auxiliary spiral The auxiliary spiral is used as reference for laying the capture spiral, the sticky silk. Most spiders will remove the auxiliary spiral silk when laying the capture spiral silk..
Capture spiral Capture spiral is the only sticky silk on the spider web. It entangled prey if they enter the web.