给你一段文本如下： 

With the increasing popularity of e-commerce, the need for effective online payment systems is crucial. Gone are the days when customers had to physically go to a store and pay for merchandise with cash or check. Nowadays, consumers can make purchases with just a few clicks. One of the most popular and widely used online payment systems is PayPal. Founded in 1998, PayPal has revolutionized the way people buy and sell goods online.

One of the key features of PayPal is its security. PayPal uses advanced encryption techniques to protect the personal and financial information of its users. In addition, PayPal offers fraud protection and dispute resolution services. If a buyer does not receive their purchased item or if the item received is significantly different from the description, PayPal offers assistance in resolving the issue. 

Another advantage of PayPal is its convenience. PayPal allows users to add multiple credit or debit cards to their account, making it easy to complete transactions without having to enter credit card information every time. Additionally, PayPal offers a mobile app which allows users to make purchases on their phones or tablets. 

Overall, PayPal is an ideal online payment system for both consumers and businesses. Its convenient features and secure platform make it a trustworthy choice for e-commerce transactions.，总结其中的关键词。
e-commerce, online payment systems, PayPal, security, fraud protection, dispute resolution, convenience, mobile app, transactions, trustworthy.