In this lesson, we create a Scratch Org.
Resources:
Build Your Own Scratch Org Definition File - https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_scratch_orgs_def_file.htm
Scratch Org Features - https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_scratch_orgs_def_file_config_values.htm#sfdx_dev_scratch_orgs_def_file_config_values
Scratch Org Settings - https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_scratch_orgs_settings.htm
Resource:
First Generation Packages vs. Second Generation Packages - https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_dev2gp_comparison.htm