EHIC stands for European Health Insurance Card, and GHIC stands for Global Health Insurance Card. Both are free and you should only use the official NHS website to apply - www.nhs.uk/ehic.
The EHIC or GHIC entitles you to free or discounted state-provided, medically necessary healthcare as if you were a resident in the country you’re visiting. Remember, this might not cover all the things you would expect to get free of charge from the NHS in the UK. You may have to make a contribution to the cost of your care. In some cases, if you use your EHIC/GHIC, certain insurers might waive the excess on your travel insurance policy.
At present, you can use the card in any country in the EEA and Switzerland, although the GHIC may become valid in more countries in the future - please check the NHS website before you travel.
More information can be found under our FAQ ‘Should I take an EHIC/GHIC?’.