It can be useful to take your GHIC abroad with you, as it gives you the right to receive discounted (or free) state-funded healthcare and treatment as if you were a resident of the country you’re visiting. See the countries that accept a valid GHIC here.
Please bear in mind that a GHIC is not a replacement for travel insurance, and it would not provide benefits such as medical repatriation or search and rescue.
The card (which is free) can be applied for on the NHS website - www.nhs.uk/ehic.