Definition - Sometimes words that come before a noun and modify it in some way are called 'determiners'. Articles, adjectives, pronouns, and other words can be used as determiners. Examples:

The German demonstrative 'dieser [this]' is used as a determiner to show 'position' in the following sentence:
             • Dieser Mann ist groß. [This man is tall.]

The German possessive 'mein [my]' is used as a determiner to indicate 'possession' in this sentence:
             • Du liest meine Zeitschrift. [You are reading my magazine.]