This is the 12918th most frequent Russian word.
летать
To fly.
In this sentence, 'летать' is used in its base meaning, representing the ability of birds to fly.
Птицы могут летать высоко в небе.
Birds can fly high in the sky.
'Летать' here expresses the action of flying, indicating a dream or desire.
Я всегда мечтал летать как птица.
I have always dreamt of flying like a bird.
Although 'лететь' is used here as the continuous action of flying, it is a more specific conjugation related to the verb 'летать'.