All institutions have different levels of access
First, you should know that every institution provides access to JSTOR a little differently. Some institutions choose to make all the content on JSTOR available to their users, some get a lot—but not all—of it, and some just get a few journals. There are also different types of content, including journals, books, and primary sources.
Our institutions have a variety of access options. Some have automatic access on campus (or on the institution’s premises), which is provided via IP authentication. A lot of them have remote (off-campus) access, too, but not all of them. You can find out if your institution does by asking at your library. There are a few different types of remote access, and an institution that provides remote access will usually have one or two types. If your institution does have remote access, you may be able to log in through our Institution Finder.