What is the difference between Invisible and Offline on Skype?

Skype: Invisible and Offline ?..

If you change your online status on Skype, two of the options are the same colour, Offline and Invisible, but what do they actually mean?

Offline on Skype means:

Everyone sees that you are Offline and you no longer have a connection to Skype. People can still call you, but you won’t get the call etc. Skype is effectively turned off.

Invisible on Skype means:

Everyone sees that you are Offline, but you are still actually online, just your Online status is invisible to everyone.  You can still use Skype and people can still call you. You have the option to answer or not answer.

Skype definition of Invisible and Offline

If you send a message to a contact and still can edit/remove this message after time longer than 1h, then this means that the contact has been Offline all the time and the message has not yet been delivered. In the case of an Invisible contact, the message will no longer be editable after the 1h timeframe has passed.

So: If you can still delete a message after One Hour, then the person is actually OFFLINE.

If the message you send cannot be deleted or edited, after One Hour, then the person is online but invisible.