1. Redis：
Redis是一个开源的键值NoSQL数据库。它是一种内存中数据结构，用于存储从内存提供的所有数据，并使用磁盘进行存储。它提供了独特的数据模型和高性能，可支持各种数据结构，例如字符串，列表，集合，哈希，可将其用作数据库缓存或消息代理。它也称为数据结构服务器。它不支持架构RDBMS，SQL或ACID事务。
2. Memcached：
Memcached是一个简单的开源内存中缓存系统，可用作临时内存中数据存储。内存中存储的数据具有很高的读写性能，并且可以将数据分配到多个服务器中。它是存储在内存中的字符串对象的键值，并且该API适用于所有语言。 Memcached对于网站而言非常有效。 Redis和Memcached之间的区别–
| Parameter | REDIS | MEMCACHED |
|---|---|---|
| Initial Release | It was released in 2009. | It was released in 2003. |
| Developer | It was developed by Salvatore Sanfilippo. | It was developed by Danga Interactive. |
| Cores Used | It uses single cores. | It uses multiple cores. |
| Length of a key | In Redis, maximum key length is 2GB. | In Memcached, maximum key length is 250 bytes. |
| Installation | It is simple and easier to install as compared to Memcached. | It may be diffcult to install. |
| Data Structure | It uses list, string, hashes, sorted sets and bitmaps as data structure. | It uses only string and integers as data structure. |
| Speed | It reads and writes speed is slower than Memcached. | It reads and writes speed is higher than Redis. |
| Replication | It supports Master-Slave Replication and Multi-Master Replication methods. | It does not support any replication method. |
| Durability | It is more durable than Memcached. | It is less durable than Redis. |
| Secondary database model | It has Document Store, Graph DBMS, Search Engine, and Time Series DBMS as secondary database models. | It has no secondary database models. |
| Persistence | It uses persistent data. | It does not use persistent data. |
| Partitioning method | It supports Sharding. | It does not support any partitioning method. |