Enabling this will allow you to be notified through e-mail when the developer changes the content of their application. This usually means that you as a translator, should come back and translate any new text that was added or changed.
This is the text that needs translation.
Click the "Translate" button to translate this text.
If available, read this description to better understand the context of the text to translate.
Besides translating the actual text, you can also commit a translation for the description. That way, users who might want to translate into their language from your language can use your description as guidance.
These are the translations already commited by other users.
If you believe you can submit a better translation that what is already available. Feel free to do so.