Does "Erase disk and install Ubuntu" option delete/erase everything on the Hard-drive?

I'm just confused. I was a Windows user pretty much all my life. But now I want to switch to Linux for good. I have a 1 TB hard-drive attached to my laptop. As you know, in windows, the total hard-drive storage is divided into a couple of drives(i.e. Drive:C, Drive:D, Drive:E etc.). Usually, Windows is stored in Drive:C. My question is if I choose the Erase disk and install Ubuntu/ubuntu-derivatives option, will it erase the data on the other drives such as Drive:D/Drive:E, or will it just erase the drives where windows/any other OS is installed and keeping the data on other drives safe ?

Only Windows confusingly calls partitions "drives". Everyone else calls partitions "partitions", and disks/drives "disks".

The erase disk option uses the term "disk" in the non-Windows sense. Everything on that physical hard drive (disk) will be erased, including all partitions regardless of what they are called.

• If "D:" is another partition on the same drive, it will be erased.
• If "D:" is on a separate drive, it won't be touched.

Other people have explained 'drive' and 'partition' in the Linux context. Anyway, "Erase disk and install Ubuntu” removes the old partition table and creates a new one. This means that the opeating system sees the memory locations as empty in the whole physical device.

But the memory cells are still containing the data that were written before (in your case while it was still formatted by Windows). It is still possible (but a lot of hard work) to recover some of these data with special tools, e.g. PhotoRec.

If you want to make it impossible to recover the previous data, you can

• overwrite the whole drive with zeros or some random data, or
• use a built-in tool in the drive to remap the links between logical memory locations and physical locations (which works like encrypting without offering a key).

Removing the old partition table and creating a new one is usually good enough, at least for personal use.

You can find more details at this link.