Filter content to get what you need

<?php
// Gets an item by its internal ID
$items = $client->getItems((new QueryParams())
  ->equals('system.id', '2f7288a1-cfc8-47be-9bf1-b1d312f7da18'));
?>

<?php
// Gets three items by their codenames. The codenames are unique per project.
$items = $client->getItems((new QueryParams())
  ->in('system.codename', ['delivery_api', 'get_content', 'hello_world']));
?>

<?php
// Gets items based on the type Product
$items = $deliveryClient->getItems((new QueryParams())
  ->equals('system.type', 'product'));
?>

<?php
// Gets items based on the types Product, Article, and News
$items = $deliveryClient->getItems((new QueryParams())
  ->in('system.type', ['product', 'article', 'news']));
?>

<?php
// Note: Date & time element values are provided by users and stored with minute precision. The system.last_modified value reflects Last content change to an item and is stored with ms precision.
// Gets items modified after April 9 2020, 9 am UTC+0
$items1 = $client->getItems((new QueryParams())
  ->greaterThan('system.last_modified', '2020-05-09T09:00:00.000000Z'));

// Gets items released at or after April 9 2020, 7 am UTC+0
$items2 = $client->getItems((new QueryParams())
  ->greaterThanOrEqual('elements.release_date', '2020-05-09T07:00:00Z'));

// Gets items modified before April 5 2020 UTC+0. Last match would be at 2020-05-04T23:59:59.
$items3 = $client->getItems((new QueryParams())
  ->lessThan('system.last_modified', '2020-05-05'));

// Gets items released at or before April 5 2020 10:30 am UTC+0
$items4 = $client->getItems((new QueryParams())
  ->lessThanOrEqual('elements.release_date', '2020-05-05T10:30:00Z'));
?>

<?php
// Gets items whose Title element value equals to 'Hello World'
$items = $client->getItems((new QueryParams())
  ->equals('elements.title', 'Hello World'));
?>

<?php
// Note: Filters work with codenames of the tags.
// Gets items tagged with one specific tag
$items = $client->getItems((new QueryParams())
  ->contains('elements.tags', ['kontent_ai']));

// Gets items tagged with a list of specific tags
$items = $client->getItems((new QueryParams())
  ->all('elements.tags', ['kontent_ai','cms']));

// Gets items tagged with at least one of multiple tags
$items = $client->getItems((new QueryParams())
  ->any('elements.tags', ['headless','cms']));
?>

<?php
// Gets items in default language with the URL slug element equal to 'sample-url-slug'
$items = $client->getItems((new QueryParams())
  ->equals('elements.url_slug', 'sample-url-slug'));
?>

<?php
// Note: Date & time element values are provided by users and stored with minute precision. The system.last_modified value reflects Last content change to an item and is stored with ms precision.
// Gets items modified between April 5, 2020 10:30 UTC and April 7, 2020, 7:00 UTC
$items = $client->getItems((new QueryParams())
  ->range('system.last_modified', '2020-05-05T10:30:00', '2020-05-07T07:00:00'));
?>

<?php
// Gets items whose rating is at least 6.5 and at most 9
$items = $client->getItems((new QueryParams())
  ->range('elements.product_rating', '6.5', '9'));
?>