diff --git a/content/notes/18-build-tools.md b/content/notes/18-build-tools.md
index 6d1ada994..942c24ac0 100644
--- a/content/notes/18-build-tools.md
+++ b/content/notes/18-build-tools.md
@@ -10,10 +10,28 @@ sr-ease: 252
 ---
 
 - understnad the purpose of build tools
+	- automate the construction of software
 - sketch how make's rules (re)build software
+	- has a set of taget and a set of sources
+	- checks whether targets are older than sources
+	- a MakeFile contains a list of commands that build the tager from the source
+	- builds in the correct order (*topologically*) e.g., will run compiler before linker
 - explain why ant better suits java projects
+	- written to handle build tasks 
+	- better at scanning sub dirs
+	- call javac on many files at once, instead of one at a time
 - sketch how maven seeks to improve on ant
+	- adds color
+	- add more conventions
+		- e.g., file structure
 - appreciated that there are many build tools
+	- rake - ruby's version of Make
+- SCons - builds database about build state
+- CMake - cross platorm building; uses existing tools/IDEs
+- SBT scala
+- languge built in tools
+	- go - Go build
+	- rust - Cargo
 
 [build-tools](notes/build-tools.md)
 
diff --git a/content/notes/19-security.md b/content/notes/19-security.md
index cb77f6ae8..9f01091f9 100644
--- a/content/notes/19-security.md
+++ b/content/notes/19-security.md
@@ -10,9 +10,16 @@ sr-ease: 250
 ---
 
 - why cybersecurity is a growing concern
+	- more software ∴ more dependecies ∴ more complex ∴ more "surface area" of risk of vulnerability
 - sketch confidentiality, integrity, and avalability security
+	- confidentiality - protecting data from being stolen
+	- integrity - attacks on data with the aim to decieve users
+	- avalability - e.g., DDoS
 - appreciate that dependencies cause security risks
+	- vulnerabilities in dependencies extend to your code
 - explain risks from non-validation of user input
+	- 
 - outline how injection attack works
+	- malicious input to manupulate underlying database
 
 [security](notes/security.md)
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