Vincent,
For me it is really hard to answer on the basis of what you posted. They both eat insects.
Geckos are lizards, but not all lizards are geckos.
Cambridge Dictionary
Gecko noun [ C ] plural geckos or geckoes
a small lizard with wide feet, found especially in warm countries
Moreover, different species can be found in different parts of the world.
I post here two pictures, which show a gecko ...
... and a lizard:
These are both pretty
common species where I live (they don't live in our houses, though!).
Do they resemble to the ones that live in your area? Do they differ from those you'd call "geckos" and "lizards"?
You might want to have a look to these two pages from Wikipedia:
Lizards and
Geckos.