diff --git a/doc/ota_updates/ota_updates.md b/doc/ota_updates/ota_updates.md
index 42bcb06ac..28aed2c9f 100644
--- a/doc/ota_updates/ota_updates.md
+++ b/doc/ota_updates/ota_updates.md
@@ -405,6 +405,15 @@ The Stream Interface is the base for all other update modes like OTA, http Serve
 
 ## Updater class
 
-TODO describe Updater class
+Updater is in the Core and deals with writing the firmware to the flash, 
+checking its integrity and telling the bootloader to load the new firmware on the next boot.
+
+### Update process - memory view
+
+ - The new sketch will be stored in the space between the old sketch and the spiff.
+ - on the next reboot the "eboot" bootloader check for commands.
+ - the new sketch is now copied "over" the old one.
+ - the new sketch is started.
+
+![Memory Copy](update_memory_copy.png)
 
-Updater is in the Core and deals with writing the firmware to the flash, checking its integrity and telling the bootloader to load the new firmware on the next boot.
diff --git a/doc/ota_updates/update_memory_copy.png b/doc/ota_updates/update_memory_copy.png
new file mode 100644
index 000000000..724637485
Binary files /dev/null and b/doc/ota_updates/update_memory_copy.png differ