In general, to interpret something is to make it personally meaningful. Our brain takes raw data from the senses and makes it meaningful by relating it to our previous experiences. When we read or hear a sentence, we put the words together into a meaningful whole, rather than just noting their separate dictionary definitions. Most everyday language is fairly straightforward and requires little interpretation. That is, they won't have different interpretations of what the article means.
Language usually requires special interpretation, however, when it is ambiguous or unclear.
Approaching literature with an inquiring attitude helps maintain this fruitful complexity. Because they respect the complexity of your own experience and the author's vision, open-ended questions are much more useful. Clearly there is no single answer for this kind of question, and your answer may change each time you read or think about the work. Although the interpretation of literature can be challenging, it may also provide unique and important rewards. Literary criticism is an extension of this social activity of interpreting.