To develop the digital economy, there must be digital infrastructure. Infrastructure must have its own physical facilities and must provide essential services, supporting economic and social activities. Infrastructure is the foundation for development. The foundation must be sufficient and must be universal.

About Vietnam's digital infrastructure. Vietnam's digital infrastructure includes: 1- Telecommunication and Internet infrastructure; 2- Data infrastructure; 3- Physical-digital infrastructure; 4- Digital transformation infrastructure. To develop the digital economy, there must be digital infrastructure. Infrastructure must have the physical facilities of that infrastructure and must provide essential services, supporting economic and social activities. Infrastructure is the foundation for development. The foundation must be sufficient and must be universal.

Vietnam's digital infrastructure includes:

1- Telecommunication infrastructure (optical cable, transmission, broadcasting station,...), Internet infrastructure (Router, DNS,...);

2- Data infrastructure (IDC, Cloud,...);

3- Physical-digital infrastructure (digitizing everything in the real world, simulating it, creating 1-1 mapping and creating interaction between the real world and the digital world (IoT to digitize everything, IoT transmission, data simulating everything (the physical world has a bridge, in the digital world there is data due to digitizing the bridge and software simulating that bridge based on digitized data), storage and processing, especially big data processing and AI);

4- Digital transformation infrastructure (Digital Utilities: digital ID, digital signature, digital payment, digital invoice, digital contract authentication, digital document).

Telecommunication infrastructure, Internet, data infrastructure are hard infrastructure, physical infrastructure. Physical-digital infrastructure includes sensors, IoT, transmission, storage, data processing are hard, but the data itself from digitized things and software that simulates things is the main part of this infrastructure, which is soft. So this infrastructure is both hard and soft. The infrastructure of Digital Utilities serving digital transformation is completely soft (software platforms). So, digital infrastructure includes both hard and soft infrastructure. The layers of digital infrastructure have hard, soft, and both hard and soft.

The biggest undertaking of digital transformation is to digitize everything in the real world, simulate it, create a 1-1 mapping and create interaction between the real world and the digital world. People have one more space to live, work, and human wealth and creative space increase at least twice. There are many things that can be done in the digital environment faster, more comprehensively and more effectively than in the real world. But there must be tools to do those things, or support the doing of those things - Digital Utilities). In cyberspace, there is also infrastructure like in the real world. Infrastructure in cyberspace is Digital Utilities.

Lesson 4: Each organization must develop its own theory.