I NEVER do icons, OK? I find them puerile.
You're not on holiday, you're working. Sometimes the length of stay depends more on schedules than anything. You usually find you're moving on more than you want unless the place is rubbish. A longhaul schedule can be quite arduous and tiring, a shorthaul schedule can be arduous and exhausting- both just as tiring in different ways.
Seniority is kept from when you join. Usually you have the choice when your seniority rises to move. Unless you change employer, you do not lose out.
All you require is here in various places. Use the search function and you will learn all about it! That's yer lot from moi.