Update ref-08-reconciliation.md

Author: cutbko

docs/docs/ref-08-reconciliation.md

@@ -116,7 +116,7 @@ renderB: <div><span key="second">second</span><span key="first">first</span></di
 => [insertNode <span>second</span>]
 ```
 
-In practice, finding a key is not really hard. Most of the time, the element you are going to display already have a unique id. When it is not the case, you can hash some parts of the content to generate an id. Remember that the id only has to be unique among its sibling, not globally unique.
+In practice, finding a key is not really hard. Most of the time, the element you are going to display already have a unique id. When it is not the case, you can hash some parts of the content to generate a key. Remember that the key only has to be unique among its sibling, not globally unique.
 
 
 ## Trade-offs