In Portugal, investing in the stock market is very easy, as all major banks allow placing market orders from a current account and hold custody of shares (for as little as €5 per quarter).
I was surprised that in the UK most banks do not provide such a service. I spent some time looking for options online and did not find what I was looking for. Some colleagues have mentioned the magic words "execution-only brokerage providers" and I did find some results.
So I know that banks and brokerage firms allow investing in the stock market. What other options are there, or what are keywords of industries that allow buying shares?
Note: I am not asking for product or provider recommendations, but some guidance on vocabulary so I can then do my own searches.