algorithm - What exactly does big Ө notation represent? -

i'm confused differences between big o, big omega, , big theta notation.

i understand big o upper bound , big omega lower bound, big Ө (theta) represent?

i have read means tight bound, mean?

it means algorithm both big-o , big-omega in given function.

for example, if Ө(n), there constant k, such function (run-time, whatever), larger n*k sufficiently large n, , other constant k such function smaller n*k sufficiently large n.

in other words, sufficiently large n, sandwiched between 2 linear functions :

for k < k , n sufficiently large, n*k < f(n) < n*k