Fiserv, Inc. is a leading global provider of financial services technology. We are publicly traded on the NASDAQ Global Select Market and part of the S&P 500 Index. We serve over 12,000 clients worldwide, including banks, credit unions, investment management firms, leasing and finance companies, billers, retailers, and merchants. We provide account processing systems; electronic payments processing products and services, such as electronic bill payment and presentment services, account-to-account transfers, person-to-person payments, debit and credit card processing and services, and payments infrastructure services; internet and mobile banking systems; and related services, including card and print personalization services, item processing and source capture services, loan origination and servicing products, and fraud and risk management products and services. Most of the services we provide are necessary for our clients to operate their businesses and are, therefore, non-discretionary in nature. Our operations are principally located in the United States where we operate data and transaction processing centers, provide technology support, develop software and payment solutions, and offer consulting services.
In 2018, we had $5.8 billion in total revenue, $1.8 billion in operating income and $1.6 billion of net cash provided by operating activities from continuing operations. Processing and services revenue, which in 2018 represented 85% of our total revenue, is primarily generated from account- and transaction-based fees under contracts that generally have terms of three to five years and high renewal rates.
We have grown our business by developing highly specialized product and service enhancements, extending our capabilities through innovation, welcoming new clients, selling additional products and services to existing clients, and acquiring businesses that complement ours, all of which have enabled us to deliver a wide range of integrated products and services and have created new opportunities for growth.