title: what is the purpose of using square brackets in json?
body: <p>I am new to json. Some json examples i have seen have data within the curly braces and some json examples have subdata within square brackets.</p>
  
  <pre><code>{
  "glossary": {
      "title": "example glossary",
      "GlossDiv": {
          "title": "S",
          "GlossList": {
              "GlossEntry": {
                  "ID": "SGML",
                  "SortAs": "SGML",
                  "GlossTerm": "Standard Generalized Markup Language",
                  "Acronym": "SGML",
                  "Abbrev": "ISO 8879:1986",
                  "GlossDef": {
                      "para": "A meta-markup language, used to create markup languages such as DocBook.",
                      "GlossSeeAlso": ["GML", "XML"]
                  },
                  "GlossSee": "markup"
              }
          }
      }
  }
  }
  </code></pre>
  
  <p>From <a href="http://json.org/example.html" rel="noreferrer">http://json.org/example.html</a></p>
  
  <p>What is the need/purpose of having data within the square brackets?</p>
  
  <p>regards</p>