Common orb weaver of which there are many, many species and variations. Though, it is related to the Garden spider that I believe a few of you are thinking of, it is not considered one. Like all spiders, it is poisonous but not a threat. Some species to get quite a bit larger and are capable of building webs that cross a small road. Ask me how I know. I thought the fucker was trying to catch a bicyclist or something.
Usually, they build their webs in the late evening and pull it down in the morning. They are generally nocturnal and unagressive towards humans. These guys eat shitloads of mosquitoes and moths, etc.
Some of them will even eat their webs while taking them down to resupply nutrients. One of the reasons they close shop in the mornings and hide is that they are a favored food supply of many species of wasps. Wasps actively hunt for these guys, as well as other spiders, fighting them, stinging them, and paralyzing them. Afteward, they return to their nest or hole, lay a single egg upon the paralyzed spider and cover it up. Fresh food when the larvae's born. nom nom