This is the 278th most frequent Catalan word.
el
"The" (masculine singular definite article).
Here, 'el' is a definite article used to specify the noun 'nen' (boy).
El nen juga al parc.
The boy plays in the park.
In this sentence, 'el' serves as a definite article for the noun 'gat' (cat) to specify it as known.
Vaig veure el gat ahir.
I saw the cat yesterday.
Here, 'el' is used as a definite article for the abstract noun 'problema' (problem).