Which word to transfer or don't?
Server only matters for WvWvW mate
If you have a question about transferring for WvW reasons you might be better off posting in the WvW subforum as they’re more likely to know.
ANet may give it to you.
As other people have said unless you play World vs. World a lot there is no need to transfer.
All the other maps (both in PvE and PvP) are shared between all the servers in your region (by which I mean NA or EU, since those are the two regions Anet has grouped servers into, there are none for specific countries or parts of the world) so you will meet people from all other servers in those maps.
If there are enough people in one map for the game to need to make multiple copies it chooses which one to put you in by prioritising people on your friends list first, then people in your guild, then people from your server, then people using the same language settings as you.
For example I’m on the EU Desolation server but I often end up in towns with people from Piken Square and Whiteside Ridge because I have friends and guild members on those servers. When I’m in PvE maps away from my friends and guildies I usually end up grouped with people from Desolation.
And when I’m playing early in the morning and most people in the UK aren’t online yet I see far more German and French speakers, because they’re 1-2 hours ahead of us so more of them are online and there’s not enough people in total to separate us into different maps.
“Life’s a journey, not a destination.”