Palliative care is any care that makes someone with a long-standing health condition more comfortable although the phrase is often associated with end of life care.
Terminal is used to define the stage where treatment of the condition is stopped and the patient will only receive 'treatment' that makes them comfortable/reduces pain & suffering. It is therefore usually definable as from the point that the doctors say 'there isn't anything else we can do' or 'what we are doing may extend life a little but not much' or 'our concern now is pain control' or whatever.
When someone is moving into the end of life phase it is really important to know when to have that conversation with the specialists, not just because of Terminal Illness cover but also because once the doctor feels someone has less than 6 months to live, there are social benefits paid by the Government. Some doctors will sign the forms once they believe the patient has less than 12 months - if the person outlives their prognosis then the benefit continues for as long as they survive. Being in the end stage is very expensive - partners or family members may have to take time off work or even give up work completely, home care and night sitters are often to be paid for, and although Social Care & Health may provide specialist beds, mattresses etc the mobility scooters / downstairs showers / wetrooms do not come cheap.
As for CI - again it varies from company to company - I tried to claim when John was diagnosed but his provider only pays out if you have G7 or higher AND are losing wages because you have been off work long enough to lose pay. As John's employer pays 6 months full pay, he was off for 12 weeks after RP and he never had any time off with the RT, he never met the threshold for payout. I was a bit frustrated at the time but then realised we should just be grateful that we didn't meet the threshold :-)