What do these code mean?

Questions and Answers
1
System Information
  • Strapi Version: 3.4.5
  • Operating System: Windows10
  • Database: MySQL
  • Node Version: 14.15.5
  • NPM Version: 6.14.11
  • Yarn Version: -

Hello community,

In this document, Backend customization - Strapi Developer Documentation
about custom service. Could you explain about these code?.

const isDraft = isDraft(data, strapi.models.restaurant);
    const validData = await strapi.entityValidator.validateEntityCreation(
      strapi.models.restaurant,
      data,
      { isDraft }
    );

What does strapi.entityValidator do?
What is validData?

Thank you.