Chapman takes a basically historical path into explaining Anglicanism, starting with Cranmer and the Reformation and then tracing other themes over the centuries (e.g. chapters on each of evangelicalism and AngloCatholicism), finishing off with a big chapter on the worldwide Anglican communion.
Chapman's account is brief but he always picks up on choice examples to illustrate his points, e.g. the changes in the wording of the eucharistic prayer between the 1549 and 1552 prayer book, to show how Anglicans moved away from the real presence, or on the hymn "The Church's one foundation" was written to bulwark one side in the Colenso controversy in the 19th century.
So while it remains an introduction to Anglicanism, he's also got enough detail to interest those who are more familiar with the subject. Indeed, most of the chapters are weighty enough to form the first chunk of reading for someone doing an A level or undergraduate essay on anything from the Reformation to the Oxford movement.
His overall thesis is that Anglicanism started as primarily a Crown-based denomination: loyalty and faith in the Crown was at its core. It is therefore struggling still to define itself now that the Crown and English state no longer give it its natural definition: within England, a key point of departure was Catholic emancipation in the early 19th Century, formalising Anglicanism as one denomination among many; within the world, the change has been the end of empire, meaning that England no longer has meaningful authority.
His explanations shed great light on the current difficulties within the Anglican Communion: why should each church agree on everything? when was that ever the expectation?
In summary, this book fabulously achieves what it sets out to do: to provide a brief introduction to Anglicanism. Because the author is so in control of his subject, he has done more than that: it's a real insight into the Anglican denomination: its blessings and its problems.