An App in Salesforce is a logical container that holds various details related to the company such as a logo, name, business operations, etc. You can customize apps to match your needs, or you can develop new applications by combining custom and standard tabs.
The process to create an app in Salesforce is given below:
Setup —> build—> Create—> App—> Click on new.
By following the above procedure, you can develop an application as you want.