most
The word 'meisten' is the superlative form of 'viel' (much) and 'mehr' (more) in German. It is used to indicate the largest amount or highest degree of something. For example, 'Das meiste Geld geht für Essen drauf.' (Most of the money goes to food.)
Most people in Germany speak German.
In this sentence, 'Die meisten' which translates as 'most', is used to denote the majority of a particular group, in this case 'people in Germany'.
That makes most people happy.
Here, 'die meisten' is used to refer to 'most people', signifying the majority of an undefined group of people.
I eat apples the most.
In this context, 'am meisten' translates as 'the most', and is used to signify something that is done in maximum quantity or frequency.