Cloud computing is when IT applications, programs and storage are delivered via the Internet. It allows users to access servers, application services, databases and storage on an as-needed basis from the comfort of their own desktop or laptop.

Few trends in technology are growing faster than cloud computing services. From billion-dollar multinational corporations and small local businesses to individuals with smartphones, cloud computing is becoming the top go-to solution for enterprises of all sizes.

According to a 2014 report from Juniper Research, 2.4 billion unique consumers used cloud-based services in 2013. By 2018, that number is projected to spike to 3.6 billion.

In dollar terms, the cloud computing market is predicted to continue accelerating worldwide, from nearly $38 billion in 2010 to more than $121 billion in 2015. In the U.S. alone, more than half of companies conduct some aspect of their business using cloud-based services.

The advantages of cloud computing

Why is cloud computing so popular? There are a number of reasons for its growing success: affordability, simplicity, flexibility, accessibility and security.

Not only is the cloud easy to use – all you need is a computer and an Internet connection – it’s also cost-efficient. Instead of investing heavily in IT infrastructure and the necessary tech support personnel, an enterprise can cut costs by migrating many of those resources to the cloud.

Thanks to economies of scale, as the number of cloud-computing customers increases, the cost of cloud services drops accordingly. A survey by Rackspace found that cloud computing saves companies an average of 23%. Moreover, a pay-as-you-go structure allows companies to track their spending and only pay for what they use.

Flexibility is a big advantage of the cloud-computing environment. The number of telecommuters, who make up about 2.6% of the U.S. workforce, grew nearly 80% from 2005 to 2012. Cloud computing allows users to access the services they need from virtually any location – a home office, a hotel room, a business meeting in Brazil – with Wi-Fi or a hard-wired Internet connection.

That kind of flexibility is becoming more important as enterprises and users increasingly tailor computing environments to their own needs. Enter everything-as-a-service, which includes numerous on-demand services such as software, infrastructure, platform, storage, disaster recovery and more.

Security is a concern for all users. We all want our files, sensitive or otherwise, to be private and protected. Despite some high-profile celebrity hacking incidents involving the iCloud in 2014, cloud storage services are considered to be largely secure. Most offer data recovery and backup options; some go further by offering the added protection of encryption.

The importance of mobility

With the rise of tablets, smartphones and software-as-a-service applications, the traditional workplace is fast becoming a hub of mobile devices and mobile employees. Nearly 40% of employees at large companies in the U.S. use three or more devices – desktop, laptop, smartphone or tablet – at work.

Technology is innovating to keep up with the burgeoning demand for mobility, and cloud computing is no different. SaaS services like Microsoft 365, for example, lets users access and edit documents and e-mails from any device, anywhere, while cloud storage services like Dropbox, Google Drive and Microsoft’s One Drive allow on-the-go users to backup data and store and sync files to the cloud from anywhere.

Streaming movies and other content to mobile phones and tablets is another piece of the cloud-computing market that services like Netflix, Amazon Instant Video and HBO GO have tapped into successfully. Of course, there’s the iCloud, but that’s exclusive to Apple products.

The cloud’s big players

With the cloud computing landscape growing and changing at Pentium processor speed, it’s not always easy to keep up with who’s who. However, with its competitive pricing and powerful computing capacity, Amazon Web Services led the pack in 2014.

In 2013, AWS recorded revenue of $3.4 billion, or 37% of the $9 billion infrastructure-as-a-service market, and that growth hasn’t slowed. Also in the top tier of cloud providers are Microsoft Azure, IBM Cloud, Google and Rackspace.

Still, with demand rising at an impressive pace, new cloud companies are popping up with some regularity. Whether they’ll succeed in an increasingly crowded field remains to be seen. At the very least, the big players will have to pay attention and adjust their offerings to stay ahead of the competition.