Let’s say that modernity has the following features, which tend to arise together fairly rapidly because they are causally linked. Their arrival is the process of modernization:

1. Instead of using a small number of traditional tools to affect nature and other people, we begin investing substantial resources in a continuous process of inventing and improving tools.
2. Traditional values–moral, spiritual, and aesthetic–are subject to doubt. One response is a fragile conservatism about the inherited values. Another is heroic creativity: making up new values. Another is imitation: self-consciously replicating values from the past or from other places. A fourth is nihilism: losing commitment to values in general.
3. Instead of assuming that roles (responsibilities and powers) derive from individuals’ social status, which people typically inherit, we view roles as the result of contracts, which can be renegotiated.
4. We become increasingly skillful at choosing efficient and effective means to a given end, but less confident about being able to choose good ends. Many people become relativists or subjectivists, assuming that ends are simply what individuals happen to want.
5. In addition to relating directly to people whom we know, we have frequent and important interactions with strangers, often via abstract media such as money or written orders.
6. People become increasingly fungible, not only in market systems but also in organizations of all kinds.
7. Social roles constantly differentiate and specialize; and complex systems develop to train, evaluate, and coordinate specialists. Many of the specialists work on inventing or improving the systems for coordinating people like themselves.

I see modernization as momentous. That sometimes makes me dissent from widely-held opinions:

1. I disagree that we are living in a time of especially rapid change, at least in the OECD countries. The really big shift occurred during modernization, which had happened in countries like the USA by 1910. Constant novelty still arises as a result of #1, #2 and #7 (above), but new tools and fashions are superficial developments compared to the wrenching shift from pre-modernity to modernity.
2. I often disagree that capitalism is the underlying cause of social problems. For one thing, the same problems occur under state socialism. If “capitalism” meant free markets, it would be something quite different from socialism. But capitalism is mainly a system in which large organizations–firms and governmental agencies–employ and coordinate specialized workers. That is a feature of modernity, not specific to market systems.
3. I have doubts about the term “postmodern.” Most of the moves made by postmodern thinkers were well known to Nietzsche and others in 1890. To be sure, the heroic, create-new-values strand of modernity was especially dominant ca. 1900-1960, and the skeptical, doubt-all-grand-narratives strand has been more prevalent since then; but both were available as soon as modernity arose.
4. I am less impressed by cultural differences across space–but more struck by changes over time–than many people seem to be. I start with the assumption that life in France and in China ca. 1500 was pretty similar, as is life in Paris and Beijing today. The big difference is before and after modernity in each country.
5. I interpret imperialism a bit differently from many people. I have no doubt that it has been exploitative, cruel, and traumatic. But I don’t see it as the imposition of “Western” culture on “non-Western” societies as much as a phenomenon of modernization. To be sure, it was much worse to be on the receiving end of colonialism and to have modernity thrust on you at gunpoint, rather than to profit as an agent of modernization. But the imperialist countries typically shed their traditional cultures by modernizing while they exerted power abroad. Today, people all over the world are just as authentically “modern” as Europeans are, and global modernity contrasts with European traditions as much as with other traditions.

Modernity is neither good nor bad; it is liberating and traumatic. It isn’t recent–we’ve had a century of it already. But it is a change compared to two centuries ago, and therefore older social theories don’t apply without serious modification.

See also: Dubai, Uganda, and today’s global political economy;  the rise of an expert class and its implications for democracy; on modernity and the distinction between East and West; Lifeworld and System: a primer; two cheers for the West; and postcolonial reaction