In the public imagination, the world of ghostwriting is closely linked with that of celebrity. The most high-profile recent example is Spare, the autobiographical work by Prince Harry, and reported to have been ghosted by the US writer JR Moehringer. At times it seems as though the association is synonymous: a ghostwriter is someone who writes memoirs, and a celebrity memoir will be ghosted.

Yet biography is far from being the only literary genre involving a ghostwriter. And in other types of work, the role of the ghostwriter may be subtly different. Specialist non-fiction is a case in point. While in the case of a celebrity memoir, the ghostwriter will often be more academically qualified than the named author, for many specialist titles, it can be the other way around. This alters the power dynamic and the editing process. Instead of constructing a narrative from a blank page, the two individuals will already have a substantial evidence base and much written material – but it may be scarcely digestible to the reader, and substantial in scale. The writing process can involve editing down and removing words.

Above all, it means clarifying terms, descriptions and reasoning. Albert Einstein once observed that if you cannot explain something to a six-year-old, you don’t understand it yourself. And we ghostwriters are happy to volunteer as the metaphorical six-year-old. As my colleague Ian Shircore wrote in this space, his client hired him because ‘we value your lack of knowledge’.

Many ghostwriters, including myself, have a background in journalism. We’re not academics. We’re not experts. This is a disadvantage. It is also an advantage. The expert has to explain the subject to us, so that we can report it in clear English. This process emphatically does not mean simplification; on the contrary, the clearer the language, the better the reader can understand nuance and complexity.

In his landmark essay Politics and the English Language, George Orwell provided inspiration and guidance to more than one generation of journalists. He observed: ‘When there is a gap between one’s real and one’s declared aims, one turns as it were instinctively to long words and exhausted idioms, like a cuttlefish spurting out ink.’

He was referring principally to the opaque language favoured by ideological factions in the world of politics, but a degree of esoteric terminology can creep into any area of human specialism.  I have found that even the most rigorous scientists and technical advisers can be prone to use allusion, metaphor and circular definitions when they are accustomed to conversing only with other experts, where there is mutual understanding and no need to define or explain.

In addition, through the writing process the ghostwriter and named author may discover a benign by-product: explaining an approach, and further discussing the implications, may result in a deeper understanding of the subject – not only on the part of the writer, but the expert too.

• Philip Whiteley is an author and ghostwriter, who pens fiction under the byline PJ Whiteley. There is more information at pjwhiteley.com