The UT Libraries buys ebooks from many providers, including individual publishers and aggregators who license titles from publishers, societies, etc. This is why ebooks do not have a single, common platform or interface, and the number of simultaneous users varies.
Most publishers, like Cambridge University Press or Elsevier, do not apply digital rights management (DRM) and user restrictions, so they are a preferred option when possible.
When ebooks are purchased through a third party, restrictions on printing, downloading, and number of users are renegotiated with the publisher on a regular basis. For some titles considered textbooks, the publishers refuse to allow more than 1 user per copy - as if you were checking out a print copy. And in some cases, publishers stop selling ebook copies of specific titles when a contract expires.
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