A "portable" version of software means it is a fully functional application that does not require traditional installation via the Windows Registry. You can store it on a USB drive, an external hard drive, or cloud storage, and launch it directly on any 64-bit Windows PC.
If you only need to view, measure, and mark up drawings on the go, the Autodesk Viewer is free and requires no installation. It is a high-performance browser tool that handles complex 64-bit files with ease. System Requirements for 2018 Versions download AutoCAD LT 2018 portable 64 bit
If you need a portable or lightweight CAD solution, consider these options instead. A "portable" version of software means it is