Application security solutions consist of the cybersecurity software (the tools) and the practices that run the process to secure applications.
On-Premise
Application security testing solutions can be run on-premise (in-house), operated and maintained by in-house teams. This approach requires organizations to provide the infrastructure, the personnel and acquire application security solutions for their usage. On-premise assures organizations that their application data is not shared with third parties and does not leave the premises.
SaaS
Application security can also be a SaaS (or application security as a service) offering where the customer consumes services provided as a turnkey solution by the application security provider. This approach doesn’t require any of the prerequisites of the on-premise approach but it does require relying partially or completely on the SaaS vendor and in most cases, allow the application data to be shared with the vendor. SaaS provides an easy way to get started on application security and can offer scalability and speed. Hybrid implementations (using on-premise and SaaS together in different projects and practices) aim to provide the best of both worlds by providing flexibility, scalability and cost optimization.