Get and Post variables let you send variables between you pages. E.g. when submitting a form, or paging through through the results of search on website.
Get variables are usually passed via a url (they can also be passed through a form when the method is set to get).
e.g. If a url was accessing the page search.lc with the url: search.lc?search=livecode, you can access the search variable like so:
<?lc put $_GET["search"] // outputs: livecode ?>
Post variables are typically passed when data is submitted via a form.
Post variables can be accessed in the exact same way as get variables, just using $_POST instead.
<?lc put $_POST["search"] ?>
Encoding GET parameters
When you are submitting data via a url, the data should be url encoded:
<?lc put urlEncode("For mice and men") // outputs: For+mice+and+men ?>