I wanted to define coaching, and then realised to first define coaching we must look at what most people first encounter within climbing.
Understanding the difference is important because although an instructor can be a coach and a coach can be an instructor, there is a difference in the delivery of tuition. In essence an instructor provides instruction and a coach, teaches based upon the client’s needs and goals.
The problem is that climbing as a leisure activity is young, especially in the UK where previously the standard path way to learn was a combination of peer learning with trial and error. There has also been a little of "it's how we've done it for years so it must be the way." To build on this, instruction has more recently been assumed to be based around hard skills such as the safety equipment and skills required to be safe such as belaying, with the presumption of coaching being about soft skills such as teaching movement.
As a practice this fails the most important part of the equation, the climber. A climber gets taught by an "instructor" who ignores their ability to climb and spends whole sessions on belaying resulting in poor motor skills when on the wall. This stunts the climbers progression from the word go. On a hard skills session it may mean a climber doesn't pick up skills the same way as the rest of the group or already has an understanding of the topic at hand and therefore has needs not met.
Also in practice a poor "coach" who spends the whole session avoiding an emphasis on hard skills and rushes to teaching movement or physical ability, as a desire to be a coach not an instructor.
The irony is a bad coach can spend a whole session instructing not teaching, and a good instructor may teach belaying with very little instruction.
The truth is the label is irrelevant, what is important is how you get taught.
A poor quality Instructor/coach
Has a heavy focus on your current task, not your long term progression. This leads to nonstop instruction without providing understanding. This could be teaching the belaying without teaching catch a fall, or telling you every move. This gives them an idea of success for them they achieved the goal of getting your hands moving so the job is good enough.
A good quality instructor/coach
So next time you are deciding whether to get an instructor or coach remember we all do the same job, we teach climbing. The more important thing to know is;
How passionate about helping you reach your goal is your tutor/mentor/coach/instructor?