One of the roles of a coach is to prepare their team to perform as well as possible against opponents and in this context the coaches of the two teams are opponents. However, there are many contexts where it is beneficial for coaches to share information and work with other coaches.

When coaching a representative team (whether regional or national) a coach is working with athletes who probably spend more of their time with another team and another coach. In this situation the two coaches should discuss:

workload and injury management for the player – both coaches should make the welfare of the player the paramount consideration;
conflicts in schedules – whether or not they can be avoided and, if not avoided, how are they best managed;
the player’s role in each of the teams – is there an opportunity at club level to work on skills that will be needed in the representative team (if the player’s role is different for each team);
the current form of the player.

It will not always be possible to avoid conflicts between a representative team and a club team, however, if the coaches can speak with each other differences can at least be both understood and minimised.

There are also other ways that coaches can work together, for example:

sharing information about other opponents;
sharing information about accommodation, travel or other logistics;
working together in scheduling games (e.g. pre-season or exhibition games);
participating in coaching clinics or other education and development activities;
discussing common issues or pressures that they face in their coaching.

Finally, having a friendship with other coaches provides a colleague with whom you can discuss trends in the game, different tactical approaches to the game and key factors in development (amongst many other things).