"Information is a message, something to be communicated from the sender to the receiver".

It must be more difficult to define data. Again, Wikipedia:

"Data is the plural of datum. A datum is a statement accepted at face value (a "given"). A large class of practically important statements are measurements or observations of a variable. Such statements may comprise numbers, words, or images".

Maybe a datum is a sort of a basic unit of information, which is either directly communicated (ie it is a part of the message, or is the message itself), or it is (part of) the input to a process which produces the message to be communicated?

Keith Devlin has a nice book about that:

Infosense: Understanding Information to Survive in the Knowledge Society.

A very readable book from which I would quote if I had not displaced it. Shall probably stumble into it when it's no longer needed.

When people say "in one ear, out of the other" or something to this effect, they mean that a process took place wherewith data has passed through our mechanisms without having any repercussions. Were it not the case, whatever had been left over in our brain becomes information, sort of recognized meaning carried by the data. After some mental process that stored this information in relevance to other pieces already stored there, the thing becomes knowledge - something that may be used for a purpose.

In other words, data is the raw stimulus. Information is the recognized specifics of the data. Knowledge is information on an operative scale.

Very recently we had an example at the CTK Exchange:

https://www.cut-the-knot.org/htdocs/dcforum/DCForumID4/656.shtml

The question was about a long string of octal digits. The string was datum. It became information when recognized as a carrier of the spherical coordinates of a point. With an additional effort, after the coordinates have been retrieved, we might have gotten knowledge there. Or, so I think.

I hope that clarifies.. :)