Cloud computing is a major shift in how companies obtain software and computing power. Instead of hosting applications and data on their own servers, companies can rent computing power, software, storage and other services from large providers over the internet. This allows companies to scale their resources up or down as needed and reduces upfront infrastructure costs. While security and reliability are challenges, the cloud computing market is expected to grow significantly in coming years as more companies and individuals use web-based applications hosted in the cloud. Major players in cloud computing include Microsoft, Google, Amazon, Salesforce and others.