Empires: total war and steam

hello, i am here because i was wondering empires: total war. my brother and i want to split the cost of the game and share it between our two computers. we have done this with every game they came out with since rome: total war. this is legal because the game require a disk to run( so only one instance of the game can exist at a time between our two computers) the problem is a steam account is neccessary for the new game to run and i was wondering whether the steam account was linked to the computer or the internet. we are not interested in buying two copies of the game when our rooms are 20 feet apart. if steam is over the internet, then cant both computers use one account?

thats the answer my brother and i wanted to hear. sharing the steam account is no problem.