An interesting definition of collaboration comes from the the very first 
pages of "Managing Collective Intelligence" by Olivier Zara, published in 2004.
I reccomend who is 
interested in go in deep about collaboration to read this book, free availble  
in PDF. Here below the definition: 
In the intelligent 
enterprise, it is important to distinguish between collective reflection and 
collective communication:
- Communication 
allows for an exchange of information, without there necessarily being any 
intellectual collaboration.
- Reflection implies 
intellectual cooperation through which information is created, becomes 
meaningful, and is applied to existing information, transforming it 
into new information.
This distinction is 
important because people often think they are cooperating when in actual fact 
they are merely communicating. Just about everyone sends and receives 
information; few are  those who engage in the more difficult act of 
co-constructing it.
 I have  also collected some other  definition of collaboration: 
this from Wikipedia:   
Collaboration is a recursive process 
where two or more people or 
organizations work together in an intersection of common 
goals , by sharing knowledge, learning and building consensus. 
[… ] teams 
that work collaboratively can obtain greater resources, recognition and 
reward 
when facing 
competition for finite resources
from other 
authors: 
•“a process 
through which parties who see different aspects of a problem can constructively 
explore  their differences and  search for solutions 
that go beyond their own limited vision of what is possible” – B.Gray, Collaborating: 
Finding Common Ground for Multiparty Problems, 
1989
•“It is a 
mutually beneficial relationship between two or more parties who work toward 
commong goals by 
sharing responsibility, authority and accountability for achieving results” – 
D.Chrislip, C.Larson, Collaborative 
Leadership, 
1994
 When you consider  a team and the projects assigned 
to them, one thing is clear: you cannot avoid to collaborate: it is mandatory 
for the success of the team. 
Results from a single serves to other people to 
accomplish their targets.  In this sense a series of facilities must be provided 
to team's people to make easiest the collaboration. 
Some of them are the classical ones: phone, e-mail, 
information broadcasting. 
Others are not entered in the common practices and 
requires some extra effort. A forum could be very useful to track discussions, a 
blog can teach new aspect of a project or the progress of an activity, etc.
Despite the himperious advent of social network, 
outside the border of the company, what is usually called as Enterprise 
2.0 is not yet perceived as an opportunity to increase productivity 
and their own business potential. 
The challenge of my job is to make these tools easier 
to use and part of the usual suite of eache collegue that works in a 
collaborative way
 
