Amazon Web Services remains the top IaaS public cloud computing provider, offering the widest breath of services of any vendor in the market, Gartner concluded in its annual Magic Quadrant report.In addition to having a broad range of cloud-based services, AWS also has the largest capacity to handle cloud-based workloads. Its cloud operation is estimated by Gartner to be five times larger than a dozen of its top competitors in the market combined. \u201cAWS is the overwhelming market share leader,\u201d the report reads. \u201cIt is a thought leader; it is extraordinarily innovative, exceptionally agile and very responsive to the market. It has the richest IaaS product portfolio, and is constantly expanding its service offerings and reducing its prices.\u201d[MORE GARTNER: Big data has pretty much reached the peak of it\u2019s Hype, Gartner says][FROM THE ARCHIVES: Do you believe in Magic Quadrants?]Each year Gartner compiles its Magic Quadrant for public cloud vendors by examining the estimated 15 largest market players based on estimated market share, then it ranks them based on their understanding of market needs and the company\u2019s ability to execute.In addition to the breadth and depth of services, AWS also has a robust partner ecosystem with leading technology providers offering its services through Amazon\u2019s cloud, including some of the biggest systems integrators. Gartner does warn of some cautions when using AWS services though, including complexity around its pricing and support offerings. Individual AWS offerings are rarely bundled, which can complicate purchasing choices.No other company is really close to Amazon in terms of its offerings, according to Gartner, but there are a variety of niche players. Outsourcer CSC, for example, receives high marks in the report and is named as the only other leader in the market. Based on VMware\u2019s suite of cloud computing offerings, CSC has a very different enterprise-focused model compared to Amazon though, Gartner says. \u201c(CSC) has a solid platform that is attractive to traditional IT operations organizations that still want to retain control, but need to offer greater agility to the business and are willing to embrace data center transformation,\u201d Gartner says. Amazon, in comparison is more of an out-sourcing play, with a limited on-premises or \u201cprivate cloud\u201d option for customers to deploy on their own premises.Microsoft and Rackspace are listed in the \u201cvisionaries\u201d category, while telco-oriented providers Verizon Terremark and Savvis are in the \u201cchallengers\u201d quadrant, along with Dimension Data. Joyent, Tier 3, Virtustream, Fujitsu, SoftLayer (now owned by IBM), GoGrid, HP and IBM are considered \u201cniche players\u201d by Gartner.The IaaS market for cloud computing is rapidly evolving, but it represents the fastest-growing need among Gartner clients. \u201cAs each provider has unique offerings, the task of sourcing their services must be handled with care.\u201d Most of the vendors included have Service-Level Agreements (SLA) that ensure the cloud will have 99.95% uptime \u2013 some even guarantee up to 99.999%.Gartner warns that security remains a major issue with cloud computing, with the extent of security measures from each provider varying significantly. While a vendor may provide some base-level of security, in many circumstances \u2013 such as with AWS \u2013 it\u2019s up to the customer to select what additional security features they want. The same is generally true with enterprise-class support, which is offered as an option for customers if they choose from many providers, like AWS.\u00a0Customers are using the cloud for more complex workloads now compared to a year ago. Gartner recommends using cloud services for purposes such as test and development, hosting cloud-native applications, e-business hosting, enterprise applications, general business applications and batch computing \u2013 depending on the provider.Senior Writer Brandon Butler covers cloud computing for Network World and NetworkWorld.com. He can be reached at BButler@nww.com and found on Twitter at @BButlerNWW. Read his Cloud Chronicles here.