I have a 250GB SSD boot drive and a 1TB SSD, both of which are NVME. I’m buying another 2TB NVME and I don’t know how clone drives so I’m planning to ask the store to clone the contents of the 1TB drive to the 2TB drive, then the 250GB drive to the 1TB SSD and use it as the new boot drive. I’ll use the 250GB SSD as an external drive. Since I’m replacing the drives, I’m not sure if cloning the drives will also clone the drive letters. If it doesn’t, do I need to bring my PC to the store to change them, or can I just remove the drives and bring them to the store? Once the cloning process is done, can I take them home and expect them to work without further configuration?"
No, the drive letter is not static. If a drive was a train, the drive letter would be the platform number where the train arrives. Or if a drive was a plane, the drive letter would be the gate number.
Windows generally assigns the same drive letter to the same device, but if you want to, you could change drive letters randomly whenever you feel like it. The only thing windows needs is that every device has a different letter so that it can differentiate between them, but it doesn’t necessarily matter which has which letter.