Search for 'coaching' on Google and you will be presented with a bewildering range of different types and approaches. One way of distinguishing them is by what they focus on:

• Skills: the focus is on developing new skills in the coachee (IT skills, management skills, etc). These skills would usually be developed by the line manager or on training courses.
• Performance: the focus is on raising the coachee's level of performance in their current role. This sort of coaching would often be provided by a person's line manager or by an internal coach.
• Development: the focus is on the coachee's long-term development. As well as helping develop competencies (the ability to utilise a skill) and capabilities (the ability to use the skill in the right way at the right time and in the right place), development coaching also helps develop capacities (human qualities such as authority and presence), the expression of which enables the person to bring more of who they are to their role. Generally provided by internal or external coaches.
• Transformation: whereas the focus in development coaching is on increasing the coachee's capacity within their current stage of development, transformation is more involved with helping them shift levels (see The 7 Transformations of Leadership for an example of such levels). This kind of coaching is usually delivered by external coaches.

It is also possible to relate these levels of leadership development - Expert, Achiever, Individualist or Strategist (for more on these levels see Rooke and Torbert's article in the April 2005 Harvard Business Review (pp 67-76) ) - to the type of coaching. More in Coaching, Mentoring and Organizational Consultancy: Supervision and Development by Hawkins & Smith, pp24-6.