This is the 108th most frequent Swedish word.
största
"Största" means "biggest" or "largest" in English.
In this sentence, 'största' is used as the superlative form of the adjective 'stor', which means 'big', and it modifies the noun 'katten'.
Den största katten i huset är min.
The largest cat in the house is mine.
In this usage, 'största' is again a superlative form, used with the noun 'inflytandet', denoting the highest degree of influence.
Hon har det största inflytandet på projektets riktning.
She has the greatest influence on the project's direction.
Here, 'största' is also a superlative form of 'stor', describing the noun 'utmaning', implying the most significant challenge.