This is the 6515th most frequent Russian word.
co
In Russian, "co" itself is not a word.
The usage of 'co(-)' here implies cooperation or doing an activity together.
Мы решали задачу совместно.
We were solving the problem together.
Here, 'co(-)' appears as a prefix in 'создала' (created) to indicate the initiation or coming together to form something.
Компания создала новый продукт.
The company created a new product.
In this sentence, 'со' is a preposition that means 'with'.