Kamelets (Kamel route snippets) are a concept originally introduced in Camel K and later moved into Camel core. It allows users to connect to external systems via a simplified interface, hiding all the low level details about how those connections are implemented.
A Kamelet can act as "source" of data or alternatively as "sink": a source allows to consume data from an external system, while a sink can let you send data to an external system or execute a particular action and get a result.
For example, a "twitter-stream" Kamelet may allow a user to consume all tweets containing a specified keyword. Another Kamelet "twitter-post" may allow the user to publish some data as a tweet. Those are simple examples: experienced Camel developers know how to map those Kamelets into Camel endpoint URIs directly. But, in general, a Kamelet is not expected to map 1:1 a Camel component. Kamelets are route templates, so they can be much more complex.
Being made of pure Camel DSL, Kamelets can embody all the logic that allows to consume or produce data from public SaaS or enterprise systems and only expose to the final users a clean interface that describes the expected parameters, input and output: just like an OpenAPI spec.
For example, a "store-orders" Kamelet may be used to consume all events related to orders created in a customer enterprise system. The Kamelet’s interface will define what parameters should be provided (e.g. filters on the type of order) and what’s the expected datashape of the produced events. Internally, the Kamelet defines how such events will be generated: it may involve connections to multiple systems using different protocols, transformations and so on. But everything will be hidden to the end user.
Kamelets are the fundamental unit of abstraction in the next-gen architecture of Apache Camel K. A system as a whole can be technically described as the set of operations that you can do with it: if you use the language of Kamelets to describe a specific system, then other users can have access to all those operations with ease, no matter how complicated is the internal logic underlying all those operations. Comparing it to the classical way of using Apache Camel, where developers used to write complex routes (containing both high-level and low-level details) to integrate systems, the Kamelet model tends to reduce the complexity by encapsulating low-level details into reusable components.
Kamelets are also expected to be rendered on visual tools that will provide additional value to the end users. They are generic connectors that can be used in multiples ways, depending on the context, so each UIs can use them for its own purpose.