Jackson Core
Package | Description
--- | ---
org.codehaus.jackson | Main public API classes of the core streaming JSON processor: most importantly `JsonFactory` used for constructing JSON parser (`JsonParser`) and generator (`JsonParser`) instances.
org.codehaus.jackson.annotate | Public core annotations, most of which are used to configure how Data Mapping/Binding works.
org.codehaus.jackson.format | Package that contains interfaces needed for dynamic, pluggable format (auto)detection; as well as basic utility classes for simple format detection functionality.
org.codehaus.jackson.impl | Parser and generator implementation classes that Jackson defines and uses.
org.codehaus.jackson.io | This package contains I/O helper classes Jackson itself uses, but that are not exposed for external reuse.
org.codehaus.jackson.sym | Internal implementation classes for efficient handling of of symbols in JSON (field names in Objects)
org.codehaus.jackson.type | Contains classes needed for type introspection, mostly used by data binding functionality.
org.codehaus.jackson.util | Utility classes used by Jackson Core functionality.

Jackson Mapper
Package | Description
--- | ---
org.codehaus.jackson.map | Contains basic mapper (conversion) functionality that allows for converting between regular streaming json content and Java objects (beans or Tree Model: support for both is via `ObjectMapper` class, as well as convenience methods included in `JsonParser`
org.codehaus.jackson.map.annotate | Annotations that directly depend on Mapper classes (not just Jackson core) and are used for configuring Data Mapping functionality.
org.codehaus.jackson.map.deser | Contains implementation classes of deserialization part of data binding.
org.codehaus.jackson.map.deser.impl | Contains those implementation classes of deserialization part of data binding that are not considered part of public or semi-public interfaces.
org.codehaus.jackson.map.deser.std | Contains public standard implementations of abstraction that Jackson uses.
org.codehaus.jackson.map.exc |
org.codehaus.jackson.map.ext | Contains extended support for "external" packages: things that may or may not be present in runtime environment, but that are commonly enough used so that explicit support can be added.
org.codehaus.jackson.map.introspect | Functionality needed for Bean introspection, required for detecting accessors and mutators for Beans, as well as locating and handling method annotations.
org.codehaus.jackson.map.jsontype | Package that contains interfaces that define how to implement functionality for dynamically resolving type during deserialization.
org.codehaus.jackson.map.jsontype.impl | Package that contains standard implementations for `TypeResolverBuilder` and `TypeIdResolver`.
org.codehaus.jackson.map.module | Package that contains classes and interfaces to help implement custom extension `Module`s (which are registered using `ObjectMapper.registerModule(org.codehaus.jackson.map.Module)`.
org.codehaus.jackson.map.ser | Contains implementation classes of serialization part of data binding.
org.codehaus.jackson.map.ser.impl | Contains implementation classes of serialization part of data binding.
org.codehaus.jackson.map.ser.std |
org.codehaus.jackson.map.type | Package that contains concrete implementations of `JavaType`, as well as the factory (`TypeFactory`) for constructing instances from various input data types (like `Class`, `Type`) and programmatically (for structured types, arrays, `List`s and `Map`s).
org.codehaus.jackson.map.util | Utility classes for Mapper package.
org.codehaus.jackson.node | Contains concrete `JsonNode` implementations Jackson uses for the Tree model.
org.codehaus.jackson.schema | Classes needed for JSON schema support (currently just ability to generate schemas using serialization part of data mapping)

Jackson JAX-RS provider
Package | Description
--- | ---
org.codehaus.jackson.jaxrs | Jackson-based JAX-RS provider that can automatically serialize and deserialize resources for JSON content type (MediaType).

Jackson XML Compatibility
Package | Description
--- | ---
org.codehaus.jackson.xc | Package that contains XML Compatibility functionality for Jackson, such as handlers for JAXB annotations

Jackson Mr Bean
Package | Description
--- | ---
org.codehaus.jackson.mrbean | Package that implements "interface materializer" functionality, whereby abstract classes and interfaces can be used as-is, and framework constructs implementations as needed.

Jackson Smile Format
Package | Description
--- | ---
org.codehaus.jackson.smile | Package that contains experimental implementation of "Binary-Encoded JSON-Like" data format handlers (parser, generator, factory produce both, supporting constants).