diff --git a/CrashCourse.md b/CrashCourse.md
index 8910e0e..fce994f 100644
--- a/CrashCourse.md
+++ b/CrashCourse.md
@@ -13,7 +13,7 @@ codium "$(Split-Path -Parent $PROFILE.CurrentUserAllHosts)\my-script.ps1"
 
 # variables
 
-[PowerShell is as case-insensitive as possible.](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_case-sensitivity?view=powershell-7.3) This means `$MyInvocation` works just the same as `$mYinoCAtiOn` among other things. Coming from a Unix background and preferring some consistency I like to pretend it is case-sensitive so in this repo I'll strive for that but it's worth keeping in mind. Especially since the Microsoft docs use case a lot in variable and cmdlet names.
+[PowerShell is as case-insensitive as possible.](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_case-sensitivity?view=powershell-7.3) This means `$MyInvocation` works just the same as `$mYinoCAtiOn` among other things. Coming from a Unix background and preferring some consistency I like to pretend it is case-sensitive so in this repo I'll strive for that but it's worth keeping in mind. Especially since **the Microsoft docs use case a lot** in variable and cmdlet names.
 
 Variables use `$` to distinguish themselves and can be set with `=`
 
@@ -55,7 +55,7 @@ param(
 )
 ```
 
-There are [a lot of different powers](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3) behind the square bracket syntax, [including custom validation](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3#validatescript-validation-attribute), but these are the basics. Parameters are not mandatory by default use `[Parameter(Mandatory)]` for that. The above param block could be used in a script like this:
+There are [a lot of different powers](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3) behind the square bracket syntax, [including custom validation](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3#validatescript-validation-attribute), but these are the basics. Use `[parameter(mandatory)]` to require one otherwise they are optional. The above param block could be used in a script like this:
 
 ```powershell
 if ($silent) { exit }
@@ -80,17 +80,62 @@ Functions use `param` too (instead of parenthesis like other languages). The las
 ```powershell
 function My-Add {
   param(
-    [Parameter(Mandatory)][int]$x,
-    [Parameter(Mandatory)][int]$y,
+    [parameter(mandatory)][int]$x,
+    [parameter(mandatory)][int]$y,
   )
 
   $x + $y
 }
 ```
 
-# For and ForEach
+# foreach
 
-# Paths and Items
+Works on [arrays](https://learn.microsoft.com/en-us/powershell/scripting/lang-spec/chapter-09?view=powershell-7.3#92-array-creation), which can be concatenated with `+` and `+=` by the way.
+
+```powershell
+$letterArray = "a","b","c","d"
+foreach ($letter in $letterArray)
+{
+  Write-Host $letter
+}
+```
+
+And also works for results from `Get-ChildItem` like when looping through files in a folder.
+
+```powershell
+foreach ($file in Get-ChildItem)
+{
+  if ($file.length -gt 100KB)
+  {
+    Write-Host $file
+  }
+}
+```
+
+# items and paths
+
+In PowerShell files and folders are called items. Some useful cmdlets for working with them are:
+
+- [`New-Item`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/new-item?view=powershell-7.3#description) - create a file or folder
+- [`Remove-Item`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/remove-item?view=powershell-7.3#description) - delete a file or folder
+- [Move, Invoke, Rename etc...](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/?view=powershell-7.3)
+
+Here's how to loop through files in a folder using [`Get-ChildItem`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/get-childitem?view=powershell-7.3#description):
+
+```powershell
+foreach ($image Get-ChildItem $path -Include *.png) {
+    Write-Host $image.BaseName
+}
+```
+
+There are also a handful of useful functions for dealing with path strings by the names of [[Verb]-Path](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/?view=powershell-7.3). Here are some examples:
+
+```powershell
+# Get parent folder
+Split-Path -Parent $path
+# Test if a file exists. For folder use `-PathType container`
+Test-Path -Path $path -PathType leaf
+```
 
 # See Also