Amazon Elasticache is primarily used for which of the following?

Amazon ElastiCache is primarily utilized for in-memory caching to enhance the performance of applications and streamline database querying. When applications need to retrieve data from a database, traditionally, this can be a time-consuming process, especially if the database contains a large amount of information. By implementing caching with ElastiCache, frequently accessed data can be stored in-memory, allowing for significantly quicker retrieval times. This reduces the load on the original database, improves response times for applications, and can reduce latency, making the entire system more efficient.

Using ElastiCache, developers can leverage caching strategies like Memcached or Redis, which can store temporary data and easily scale with increasing application demands. This capability is essential for high-traffic applications where performance and speed are critical.

The other options, while having their place in cloud architecture, do not align with the primary function of Amazon ElastiCache. Data warehousing, backup and restore services, and web hosting serve different purposes and do not focus on the caching of data to improve performance and speed, which is the core advantage of using ElastiCache.