Key features:
License type:

Portable electronic license (E-license): A portable license allows the user to transfer the license to the new device if they switch to a new computer. This is a convenient option because the license transfer between devices can be easily done on the Microsoft website or through customer service, without having to purchase a new license.
Applications:
The Office 2019 Professional Plus package includes the following programs:

Microsoft Word (word processor)
Microsoft Excel (spreadsheet manager)
Microsoft PowerPoint (presentation creator)
Microsoft Outlook (mail, calendar, and task management)
Microsoft Access (database manager)
Microsoft Publisher (publication editor)
Skype for Business (corporate communications)
Electronic license (E-license):

The product license is not sent on a physical medium, but electronically (by email). The activation code and license information are received electronically by the user.
During activation, the license key must be entered via the Internet, and Office 2019 is activated on the given computer.
Portability:

The advantage of a portable license is that if the user switches to a new computer, the software license can be transferred to a new device. This does not require the purchase of a new license, and Microsoft customer service can help with the transfer.
The license provides the use of the product with a one-time purchase, and if necessary, it can be transferred to another device if the current device is no longer usable or outdated.
Telephone Activation:

Although the electronic license allows online activation, telephone activation is also an alternative if some problem occurs during online activation or if the user does not want to activate online. In such cases, the user must contact Microsoft Customer Service by phone.
Lifetime License:

The product is valid with a one-time purchase, so the license remains valid forever. There is no monthly or annual subscription required, and there is no limit to the duration of use for users.
Updates and Support:

Office 2019 receives security updates and patches from Microsoft, but does not include access to new versions (e.g., it cannot be upgraded to Office 2021 or Microsoft 365). The product does not include free access to new versions, so new Office versions (such as Microsoft 365) may incur additional fees.
Uses and Benefits:
Portability: The biggest advantage is that the user can move the license to a new computer if necessary. This is useful,for example, if your device breaks down or you buy a new device and don't want to buy a new license.
One-time purchase, long-term solution: Office 2019 Professional Plus is valid forever with a one-time purchase, so the user doesn't have to worry about subscription fees.
Convenience and easy installation: The electronic license and online activation provide a convenient way to install and manage the license.
Summary:
Microsoft Office 2019 Professional Plus - Portable Electronic License is an ideal choice for those who want to use Microsoft Office applications long-term with a one-time purchase, but want flexibility in terms of transferring the license. The electronic license provides quick installation and easy activation, while portability allows you to move the license to another device if necessary.