WIP

3.md

@@ -176,7 +176,9 @@
   - Baselining
     - "Baselining is the process of determining a standard set of functionality and performance. This is a metrics-driven process, where later changes can be compared to the baseline to gauge their impact on performance and other variables." (Conklin)
   - Immutable systems
+    - "An immutable system is a system that, once deployed, is never modified, patched, or upgraded. If a patch or update is required, the system is merely replaced with a new system that is patched and updated." (Conklin)
   - Infrastructure as code
+    - "Infrastructure as code is the use of code to build systems, rather than manually configur- ing them via normal configuration mechanisms. It is a way of using automation to build out systems, reproducible, efficient and is a key attribute of enabling best practices in DevOps." (Conklin)
 - Version control and change management ([James Messer](https://www.youtube.com/watch?v=iTYTgEBnfUM&list=PL5ysgoFoCpZEM8cboeHdRDePc2bOU9CN1&index=79))
 - Provisioning and deprovisioning ([James Messer](https://www.youtube.com/watch?v=lqk6hcAIjVw&list=PL5ysgoFoCpZEM8cboeHdRDePc2bOU9CN1&index=80))
 - Secure coding techniques ([James Messer](https://www.youtube.com/watch?v=RTifWn01l2g&list=PL5ysgoFoCpZEM8cboeHdRDePc2bOU9CN1&index=81))