A rhythmic grid is like a stencil that you can mentally put on music. The ability to do this correctly depends on the experience of listening to music in different styles, experience of playing musical instruments or creating electronic music, or dancing. But simply with the correct imposition of this stencil, the music becomes logical and understandable. Even if it is full of syncope and accents on weak beats. The strong beat can be felt even when there is nothing there.
For some music, everything is quite obvious and even, and different instruments emphasize the strong beat, there is the kick of the kick, the root of the bass and the chord change also happens there. But in some styles, on the contrary, everything is more confusing and cunning. For example, the song of The Police - Walking on the Moon, in it only hi-hat goes to the first beat, which plays eighths, and the kick goes to the second and fourth quarters, their drummer Stuart Copeland scooped all these things from reggae. But the bass (on which Sting is playing) quite clearly denotes the strong beat, starts from the bar, but the tonic is on the first beat.
In general, the overall picture is perceived as a result.
The entire musical rhythm is divided into strong and weak beats ("one-and-two-and" ...), well, except for all kinds of dubsteps ...
This helps to highlight the rhythm itself and the timing distribution rhythm, since there are different beat rhythms (3 / 4,2 / 3,4 / 4 ...).