What is Unity exactly?

Question

I have a few questions about Unity.
1. Is it in your browser or do you need to dowload it?
2. If you need to download it, how much space do you need to do so?
3. Does it work on all computers or do you need specific specs?
4. Are there programming languages you need to learn before starting with Unity?

Sorry if this are stupid questions.

Answer 1

1, 2 and 3.

https://unity3d.com/get-unity/download

Just in case you missed the download page:

System Requirements for Unity version Unity 2019.1.12

Released: 26 July 2019
OS: Windows 7 SP1+, 8, 10, 64-bit versions only; macOS 10.12+
GPU: Graphics card with DX10 (shader model 4.0) capabilities.

4. C#