Merge pull request #248 from aturner-epcc/aturner-epcc/dependency-i201

Adds callout to define dependency. Closes #201

episodes/introduction.md

@@ -45,6 +45,17 @@ scientific software (or software in general!) for your research. Then,
 share with your neighbors and try to come up with a list of common gripes or
 challenges.
 
+::::::::::::::::::::::::::::::::::::::::::::::::::
+
+:::::::::::::::::::::::::::::::::::::::::  callout
+
+## What is a software *dependency*?
+
+We will mention software *dependencies* a lot in this section of the workshop
+so it is good to clarify this term up front. A software dependency is a
+relationship between software components where one component relies on the
+other to work properly. For example, if a software application uses a library
+to query a database, the application depends on that library.
 
 ::::::::::::::::::::::::::::::::::::::::::::::::::
 
@@ -66,6 +77,8 @@ or missing piece may stop the whole thing from working or break something that w
 already running. It's no surprise that this situation is sometimes
 informally termed **dependency hell**.
 
+
+
 :::::::::::::::::::::::::::::::::::::::  challenge
 
 ## Software and Science