Docs > Redis > Data-types > Redis data types
Redis is a data structure server. At its core, Redis provides a collection of native data types that help you solve a wide variety of problems, from caching to queuing to event processing. Below is a short description of each data type, with links to broader overviews and command references.
If you'd like to try a comprehensive tutorial, see the Redis data types tutorial.
Core
Strings
Redis strings are the most basic Redis data type, representing a sequence of bytes. For more information, see:
- Overview of Redis strings
- Redis string command reference
Lists
Redis lists are lists of strings sorted by insertion order. For more information, see:
- Overview of Redis lists
- Redis list command reference
Sets
Redis sets are unordered collections of unique strings that act like the sets from your favorite programming language (for example, Java HashSets, Python sets, and so on). With a Redis set, you can add, remove, and test for existence O(1) time (in other words, regardless of the number of set elements). For more information, see:
- Overview of Redis sets
- Redis set command reference
Hashes
Redis hashes are record types modeled as collections of field-value pairs. As such, Redis hashes resemble Python dictionaries, Java HashMaps, and Ruby hashes. For more information, see:
- Overview of Redis hashes
- Redis hashes command reference
Sorted sets
Redis sorted sets are collections of unique strings that maintain order by each string's associated score. For more information, see:
- Overview of Redis sorted sets
- Redis sorted set command reference
Streams
A Redis stream is a data structure that acts like an append-only log. Streams help record events in the order they occur and then syndicate them for processing. For more information, see:
- Overview of Redis Streams
- Redis Streams command reference
- Redis Streams tutorial
Geospatial indexes
Redis geospatial indexes are useful for finding locations within a given geographic radius or bounding box. For more information, see:
- Overview of Redis geospatial indexes
- Redis geospatial indexes command reference
Bitmaps
Redis bitmaps let you perform bitwise operations on strings. For more information, see:
- Overview of Redis bitmaps
- Redis bitmap command reference
Bitfields
Redis bitfields efficiently encode multiple counters in a string value. Bitfields provide atomic get, set, and increment operations and support different overflow policies. For more information, see:
- Overview of Redis bitfields
- The
BITFIELD
command.
HyperLogLog
The Redis HyperLogLog data structures provide probabilistic estimates of the cardinality (i.e., number of elements) of large sets. For more information, see:
- Overview of Redis HyperLogLog
- Redis HyperLogLog command reference
Extensions
To extend the features provided by the included data types, use one of these options:
- Write your own custom server-side functions in Lua.
- Write your own Redis module using the modules API or check out the community-supported modules.
- Use JSON, querying, time series, and other capabilities provided by Redis Stack.