The Open Systems Interconnection model is a model that allows the IT community to understand how our networks operate and separates the model into seven layers.
Layer 7 is the Applications layer.
This is where we all operate in our daily lives. We open up our preferred internet browser (i.e. Chrome, Internet Explorer, etc.) and start to browse the internet or research, etc. Another example would be the use of Skype or Microsoft word. We use these applications on a daily basis.