What is the meaning of ?

The Korean topic marker, with various nuances according to context:

  1. Used to mark an already known topic, to which the subsequent statement applies.
  2. Used in comparative or contrastive constructions.
  3. Used with an emphatic sense.

Used to mark an already known topic, to which the subsequent statement applies.

Used in comparative or contrastive constructions.

Used with an emphatic sense.

A realis gerund suffix:

  1. what is, what was, what has, etc.; used to nominalize verbs in the realis mood.
  2. which is, which was, which has, etc.; used to make verbal adnominals in the realis mood.

what is, what was, what has, etc.; used to nominalize verbs in the realis mood.

which is, which was, which has, etc.; used to make verbal adnominals in the realis mood.

Source: wiktionary.org