# Glossary * Front-end - browser based environment (think HTML, CSS, jQuery) * Back-end - desktop and server based environment (Ruby, Rails) * Scripting language - language which default implementations run then die (Perl, Python, PHP, Ruby) * Compilation language - language which default implementation stays alive (Java, C) * Blocking - waiting for something to complete and not being able to do other things (waiting in line) * Non-Blocking - waiting for something to complete and being able to do other things while you wait (waiting via callout system) * Asynchronous - able to break off from the main flow of doing something (fork in a river) * Synchronous - stays with the main flow (curve in a river) * Parallel - multiple things happening at the same time (multi-tasking) * Serial - things happen in order, one after the other (single-tasking) * AltJS - languages that aren't javascript but become javascript through a compilation/transformation process (CoffeeScript) * High-level - abstractions have obscured away the difficulties and challenges into a nice interface * Low-level - you're provided with the bare minimum, difficulties and challenges are solved by you * API (Application Programming Interface) - the things you call to do something with something --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://learn.bevry.me/hands-on-with-node.js/glossary.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.