This electronic book has many of the features of a bound paper book.  Some of these features include the following.

• The book has a start page.  Everything normally happens from there.
• The book is organized into chapters, and within the chapters are sections.
• On the main page, at the left, is a sequence of buttons.  Normally, they should be visible at the left.  The chapters can be accessed using those buttons.
• Basic concepts - covers voltage, current, etc.
• Elements - like resistors, capacitors, operational amplifiers, logic gates, etc.
• Logic - gates (again) and digital representations, etc.
• Time and Frequency - time and frequency response of circuits
• Measurements - measuring electrical quantities, instruments, etc.
• Within each chapter are various sections, and once you click a chapter button, you get a page with links to the various sections and subsections within the book.
• There is an Index
• This is the top button at the left.  It takes you to various points within the book.  Unlike an index in a printed book, there are no page numbers.  Instead, entries in the index are live links to a point within the book.