To get started, let's take a look at the definition of a protocol and an application.
A protocol in IT terminology is a set of rules and agreements used by protocol participants. At the moment, there is a huge number of various protocols. For example,
TCP/IP is one of the protocols for data transmitting over the Internet,
SMTP is one of the protocols for e-mail services provisioning,
VOIP is a group of protocols for transmitting voice traffic over the Internet.
An application is a software or a program that a user interacts with. For example, Facebook is a web and mobile application that exists over various Internet protocols. In our article, we only take into consideration web and decentralized applications (dApps), because they require network interaction for their operation and, therefore, they use network protocols or, in the case of dApps, protocols of a particular blockchain network.
An application, in turn, is software or a program that a user interacts with. For example, Facebook is a web and mobile application that exists over various Internet protocols. In our article, we are only talking about web and decentralized applications (dApps), because they need network interaction for their work and, therefore, they use network protocols or, in the case of dApps, protocols of a particular blockchain network.
The relationship between a protocol and an application can be easily described as follows: an application is something that exists above the protocol level.