This is the 13677th most frequent Polish word.
podcast
A digital audio or video program available for streaming or download, often released in episodes.
'podcastu' is the singular genitive form used after the verb 'posłuchałem' (I listened to), which typically takes the genitive case for its objects.
Posłuchałem ciekawego podcastu o nauce języków.
I listened to an interesting podcast about language learning.
'podcast', as used in the nominative singular form, is directly the subject of the action of 'prowadzi' (hosts).
Michelle prowadzi popularny podcast o zdrowym stylu życia.
Michelle hosts a popular podcast about healthy living.
Here, 'podcast' appears in its nominative singular form once again and is the object of 'stworzyć' (to create).