Pal and NTSC are different systems for the display on a television screen. They are something to do with the number of lines displayed.
Because of this, there was a problem playing American VHS tapes on English equipment as it was trying to play a different signal which the equipment wasn't designed to decode.
When DVD players first appeared, ones sold in the UK were all PAL output. There was also the problem caused by commercial recordings being deliberately coded to play only in equipment sold in specific countries. Region 1 being USA and Canada. Region 1 DVDs would not play on UK players.

Since then, various player manufacturers hav sold models which solve some of these problems. Some players are Multi-Region, so will play US discs as well as UK ones. Some players have the capability to output both PAL and NTSC.
What I am not sure is how many do and how many do not.

In other words, Rapaire, I think that the DVDs may play perfectly well if the recipient has a compatible set of equipment, but there is no guarantee that their set-up WILL be one which works. It could be down to luck and could also be dependent on the coding of the DVD.

Then again, somebody may be more up to date on technology than I am, and tell you that I am giving an assessment of the situation that is no longer accurate.
Quack!
Geoff the Duck.