diff --git a/src/types.js b/src/types.js
index 0e4cc37..7d91d3e 100644
--- a/src/types.js
+++ b/src/types.js
@@ -8,10 +8,14 @@
  */
 
 /**
+ * Vuex state.
+ *
  * @typedef {Object.<String, *>} State
  */
 
 /**
+ * URL query parameter object.
+ *
  * @typedef {Object.<String, *>} QueryParams
  */
 
@@ -33,15 +37,19 @@
  */
 
 /**
+ * A last location object.
  *
  * @typedef {Object.<String, *>} LastLocation
  */
 
 /**
+ * An array of location history objects
  *
  * @typedef {Array.<Object.<String, *>>} LocationHistory
  */
 
 /**
+ * Multiple arrays of location history objects mapped to user and devices.
+ *
  * @typedef {Object.<User, Object.<Device, LocationHistory>>} MultiLocationHistory
  */