Nowadays Wireless Sensor Networks (WSN) users are becoming more exigent when choosing services for a certain WSN application. This paper describes the characteristics of WSN services and applications, splitting them into six main characteristics and each main characteristic is identified by specific parameters that identify the main characteristic. For each parameter a description is made in order to better understand how services are described and differentiate from each other and examples are given, referring the importance of these parameters in the services that are offered to the user. The gathering of all these parameters allowed us to sketch up taxonomy for the services in WSN regarding the applications, allowing the user to choose the application he/she wants based in these categories whilst identifying the services offered by the application. Future work will aim the detailed characterization of services offered to the main areas of WSNs considering these parameters and also on others parameters yet to be included.