E-books take many forms.
Most e-books, often part of collections or in databases, are fully searchable, and
Many e-books duplicate printed texts, others are born digital and provide unique access. See:
The Penn Libraries link to freely available e-book collections such as Gutenberg-e and Project Gutenberg, but most e-books are purchased by the library and you will need to enter your penn key to open them.
To find e-books in the Penn Collections
Some of these links may require a Penn key