What is context and why is it important when studying a text, for example Romeo and Juliet?

The simple definition of context is the background information surrounding a subject. When studying a literary text, context can apply to either historical context: what was taking place around the time a text was written (and in the case of Romeo and Juliet, performed), and how does this impact our reading of the text? You can specifically look at historical, cultural, social or political contexts, but for this level a general context is usually a mixture of all four aspects. 

The reason that context is important when studying literature is that it gives us an idea of what was going on around the time that the text was produced. Especially when it is an older text, such as a sixteenth-century play like Romeo and Juliet, life was very different to modern times. If we do not have at least a basic understanding of sixteenth-century England, as readers and as audiences we will struggle to understand what the play is trying to say to us, or what comments Shakespeare may have been making about his society when he wrote this play. To take an example of social and/or cultural context - society in early modern England was much more patriarchal (male-centred) than it is today. As we study Romeo and Juliet, knowledge of what life was like for women in the 1500s, and the expectations placed on them, especially regarding marriage, can help us gain a deeper understanding of the play, as love and marriage are of course two of its major themes.