How do you know what kind of spider your spider is?

Answer 1

examine it. what color is it? does it have long or short legs? are there any markings on its back, belly or legs? what shape is it? is it big or small? once you answer some of these questions type your description into the search bar of Google.com and pictures and websites of similar Spiders will appear. check to see if any are your spider!

Use Google or other search engines to search for

spider

and

keys

That should lead you to a key (system of questions that gradually narrows down the possibilities). There are also "spider identification" "sites".