Modern Applied Science; Vol. 12, No. 3; 2018 ISSN 1913-1844 E-ISSN 1913-1852 Published by Canadian Center of Science and Education 175 Web Services: A Comparison of Soap and Rest Services Festim Halili 1 & Erenis Ramadani 1 1 Faculty of Natural Sciences and Mathematics, Department of Informatics, University of Tetova, Macedonia Correspondence: Erenis Ramadani, Faculty of Natural Sciences and Mathematics, Department of Informatics, University of Tetova, Macedonia. E-mail: festim.halili@unite.edu.mk, erenisramadani@gmail.com Received: December 12, 2017 Accepted: December 23, 2017 Online Published: February 28, 2018 doi:10.5539/mas.v12n3p175 URL: https://doi.org/10.5539/mas.v12n3p175 Abstract The interest on Web services has been growing rapidly in these couple of years since their start of use. A web service would be described as a method for exchanging/communicating information between devices over a network. Often, when deciding which service would fit on the architecture design to develop a product, then the question rises which service to use and when? SOAP (Simple Object Access Protocol) and REST (Representational State Transfer) are the two most used protocols to exchange messages, so choosing one over the other has its own advantages and disadvantages. In this paper we have addressed the differences and best practices when to use one over the other. Keywords: SOAP, REST, XML, HTML, Client/Server 1. Introduction In these days of modern technology development, there are a lot of ways that can be used to create enterprise applications. The choice of selecting one over the other should be solely based on technical arguments and their capabilities delivered by each alternative. Thus, web services have gained an enormous popularity in how devices communicate between each other. Briefly, web services (Mironela, 2009) are self-describing and modular business applications exposing business logic as a service over the Internet. They are delivered through programmable interfaces, while their functionality can be consumed and invoked through their IP address. (Wagh, 2012; Halili & Dika, 2012) There are a lot of technologies that can make this communication possible, such as RMI (Remote Method Invocation), CORBA or DCOM. But, when it comes to security or compatibility, these technologies seems to cause a lot of troubles. Instead, the modern technology is generally based on two new models: SOAP and REST. (Tihomirovs & Grabis, 2016) Both, SOAP and REST are based on service-oriented architecture. Their development process includes something called Web API, which represents the interface for consuming their service. Various applications such as conferencing, web or social applications can be developed using these web services, because there is not required any prior knowledge before usage, what makes them platform independent and loosely coupled. (Adamopoulos, 2014) SOAP is designed to be a lightweight, platform independent protocol for decentralised, distributed environment which uses Internet and XML to exchange information between nodes. It represents a messaging protocol, which uses XML to define the communication and HTTP to transmit these messages. It is a stateless, one-way message communication between nodes or devices, from sender to receiver. (Halili et al., 2012) In the other hand, REST represents a client-server architecture where the client sends the requests, while the server processes them and returns the responses. It was introduced in 2000, by Roy Fielding. Unlike SOAP, REST services does not limit itself to XML, instead, it also supports JSON (JavaScript Object Notation), plain text, etc. (Halili & Kasa, 2011) In this paper we will compare the two services and explore the differences that they have in the underlying technology, implementation, strength and weaknesses. The paper is organized as follows. In the sections 2 and 3 I will provide information about SOAP and REST web services, their advantages and disadvantages. In section 4 will be shown a comparison table, and the paper is