Eastercon is the British national convention, and moves around the united kingdom every year, with different groups organizing it. This year will be in Scotland and is called Satelite 4 I have applied to be on the program, but doubt i will get much. Most of my time will be pushing Shamrokon.
Worldcon, is a convention that moves around the world, though tends to be US based. This is a historical thing, and this is changing. This year is in London, Loncon 3, next year is in Spokane (Washington state),Sasquan. This is basically one of the longest running Science Fiction and Fantasy conventions in the world. the First one occurred in 1939 at the New York Worlds Fair, this is where the name originally came form.
So my two international cons this year are both in the UK. I had hoped to make it to Swecon (Swedish National Convention) in June, or to Finncon (Finnish National Convention) in July, but looking at finances that is almost certainly not going to happen.
Locally I will probably get to a number of Dublin Gaming and Anime cons. Will try to get a Ticket for Dublin Comic Con as well.
I will also be at Shamrokon which is taken place at the end of this August .