Starting on April 6, the series is displayed on the search engine's homepage for two weeks as a gesture of gratitude.

As quoted from Google’s news portal 9to5google.com, the Doodles honor essential frontline workers, including healthcare workers, first responders and those keeping services such as people working in sanitation, food service, public transit and more.

The Google Doodle series are usually reserved for multi-week sporting events such as the Olympics and World Cup.

Read also: Google Doodle spreads handwashing, recognizes 'father of infection control'

The first appreciation Doodle on April 6 was dedicated to public health workers and researchers in the scientific community.

Google Doodle for public health workers and to researchers in the scientific community (Courtesy of/Google)

In the following days, the Doodle paid tribute to doctors, nurses and medical workers; emergency services workers; custodial and sanitation workers; farm workers and farmers; and grocery workers.

Google Doodle for grocery workers. (Courtesy of/Google)

On Tuesday, Google is saying thank you to all public transportation workers.

Google Doodle for public transportation workers. (Courtesy of/Google)

Four months into the year and the COVID-19 crisis, the world is still fighting hard for recovery.

Almost all countries across the globe have reported COVID-19 cases, with more than 1,8 million cases and 114,980 deaths recorded. (gis/wng)