Perhaps I may point out two distinctly different types of time, and the idea of pulse/beat.. Not that it hasn't been mentioned, but perhaps not so directly.. (though this may still be fairly rambled

)
Simple time, where each beat is divisible in groups of 2 pulses of the smaller unit. As in 4/4, where there are 4 crotchets beats, each divisible in to a group of 2 quavers. Creating 4 groups of 2 quavers, or 8 quaver pulses... 4 beats, 8 pulses.
Common examples of "simple time" where the divisions of beats into two pulses are signatures such as 4/4, 2/4, 3/4, 2/2, 3/2, 3/8.
This is as opposed to "compound time" - where each beat is divisible into 3 pulses. Examples are perhaps signatures that have a number 6 or higher on top. 6/8, 9/8, 12/8.
These "compound" time signatures can (perhaps subjectively) be read to be 'felt' in a similar way to there 'simple' counterparts.
6/8 is the same (well, similar yet completely different) as 2/4
9/8 is the same as 3/4
12/8 is the same as 4/4
But, in the compound signatures, rather than crotchet beats there are dotted crotchet beats - or groups of three quavers.
_____________
Each set here containing the same number of beats but a different number of pulses within each beat.. simple with crotchet beats, compound with dotted crotchet beats
2/4 - Ti-ti Ti-ti (2 crotchet beats, split into 2 lots of 2 quavers)
Strong Weak
6/8 - Ti-ti-ti Ti-ti-ti (2 dotted crotchet beats, split into 2 lots of 3 quavers)
Strong Weak
....
3/4 - Ti-ti Ti-ti Ti-ti
Strong Weak Weak
9/8 - Ti-ti-ti Ti-ti-ti Ti-ti-ti
Strong Weak Weak
....
4/4 - Ti-ti Ti-ti Ti-ti Ti-ti
Strong Weak Medium Weak
12/8 - Ti-ti-ti Ti-ti-ti Ti-ti-ti Ti-ti-ti
Strong Weak Medium Weak
In music with a compound signature and a slowwww tempo, the dotted crotchet feel still exists but it is less apparent - you are more likely to say, in 6/8, actually feel 6 beats, rather than 2 beats and 6 pulses, but even so there will be a rhythmic feeling of S-w-w S-w-w