UK General Data Protection Regulation (UK GDPR) is tailored by the Data Protection Act 2018. The GDPR was brought into UK law as the "UK GDPR". Data collected after the 1 January 2021 will need to comply with the UK GDPR alongside the DPA 2018. The EU GDPR is still apply directly to you if have users and customers in Europe.
The UK-GDPR is the same law as the European GDPR, and changed to accommodate domestic areas of law after Brexit.
The core definitions and legal terminology such as personal data, rights of data subjects, data controller, data processor, legal bases of data processing, consent requirement are the same.
UK-GDPR expands GDPR to areas: National security, Intelligence services, Immigration. These areas are out of scope of EU GDPR but within the scope of UK GDPR.
The regulator of UK-GDPR is UK ICO (Information Commissioner's Office), instead of European Data Protection Board (EDPB) in the EU after Brexit.
UK-GDPR is that the age of valid consent is lowered to 13 years in the UK compared with 16 years in the EU.
For internet companies have UK and EU users and customers, both UK GDPR and GDPR are requried to comply.
What is valid consent? by ICO UK
Why is consent important? by ICO UK