The msvcp140_1_app.dll file is a part of the Microsoft Visual C++ Runtime Library, specifically a variant intended for Universal Windows Platform (UWP) applications. This Dynamic Link Library (DLL) is crucial for running programs that are built using Microsoft's Visual Studio software and depend on certain features and functionalities provided by the C++ Standard Library. The file contains compiled C++ code and routines like string manipulation, input/output, and memory management that the programs can call upon. If you are a user trying to run a UWP application and encounter an error related to this DLL file, it generally means that the program you are trying to execute requires functionalities that are contained within this library. The absence or corruption of this DLL could result in errors or the program not running at all.

Developers include these runtime libraries to ensure their programs can carry out certain tasks without having to "reinvent the wheel." This library is usually distributed with the software package or should be installed through Microsoft's redistributable packages. It's an essential component for running UWP applications that rely on C++ programming and is a typical requirement for many modern software packages created using Microsoft's Visual Studio.