Terminology - what do we call the source [sic?] site/database?

Another wording:

"site to import" and "database to import".

I use source or legacy interchangingly as the situation demands. In database spec, I use 'legacy' whereas when talking about it, I use the word 'source'.

Given the general meaning of the word 'migrate', I think 'source' is more apt to describe the place from where the data moves.

+1 for source from me.

if it's a vote, +1 for source :)

Ok, "source" is correct in code. I agree fully.

But please think on the UI (user interface) as a UI. This is, what we see, when we want to upgrate from D6 or D7 to D8.

There may be many people, which have to change e.g. from D6 to D8. They run D6 for years without changes. Now (in 2015) they have to use the new (thanks!) migration.

Did they know, what is "source"? Or can it be better, to change the wording in the UI?

Could they understand "site to import" and "database to import" or "site to upgrate" and "database to upgrate" in the UI?

Wusel

Adding:
This is an import and not an upgrate! The old database does not change during the migration. If we upgrate e.g. from D6 to D7, then the old database is after the upgrate the "new" database. This is a difference!

This might be a cultural thing but I feel that "source database" is the most apt phrase out of the options we have (or that I can think of). I like the phrase "site to import" or "site to upgrade" even though it is a mouthful, but I think it might be confusing as site might mean different things. We could probably say "Address of the site to import", but that is too much and we are saying as much in the description anyway.

Between "site to import" and "site to upgrade", I would prefer the "import" version as "upgrade" somewhat suggests that the upgrade will be made on the same database, which is misleading.

My preference in order:

1. Source Site
2. Site to Import

+1 for source.

I will go for "Source". As it is more meaningful from migration perspective.

Source database makes most sense for me.