Centering QR code component with -ms-transform

What are you most proud of, and what would you do differently next time?

I am just proud I managed to match the design :)

What challenges did you encounter, and how did you overcome them?

There were some little challenges like working with Git, nothing to write home about.

What specific areas of your project would you like help with?

Although the project was simple to do, centering an element vertically and horizontally seems to be more complicated than it should. Using flex is possible (I think), but I decided to use positioning:

.container {
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

I understand the transform property, but I don't understand what is -ms-transform property supposed to be and what does it do. If anyone has an answer or has a link with a good explanation, I am happy to devour it :)