The definition is below from the dictionary. The 1104 doesn't come with an index. It comes with a contents. An index is what you find in the back of a book or manual that is alphabetized. It is like key words from each paragraph not included in the contents. Using an index is very beneficial. I believe an index is way more efficient than tabs. Sure I use tabs and can get to a section with a tab, but then you need to scan the paragraphs for the info needed. With an index it takes a few seconds to find the key word, and now you know precisely where the information needed is. For example, if information is needed for radiographic film using heat shields, you look under Radiography in your index, alphabetized under it you would find "heat shield", next to it would be 11.1.2.2 section(i)pg 30, 11.1.2.3 section(j)pg31, 11.1.6.1 section(c)pg32. If you didn't know the exact location of the information you needed, you would have had to look thru the whole section under film which is large enough to waste time on.
in·dex·es or in·di·ces (-d-sz)
1. Something that serves to guide, point out, or otherwise facilitate reference, especially:
a. An alphabetized list of names, places, and subjects treated in a printed work, giving the page or pages on which each item is mentioned.
b. A thumb index.
c. A table, file, or catalog.
d. Computer Science A list of keywords associated with a record or document, used especially as an aid in searching for information.