It means that the strong beats are on 2 and 4. If you can't hear that, then I honestly don't understand why you can't. Perhaps you should compare some recordings of modern rock and R&B to Western classical music, Mexican banda, the waltz, the polka, the foxtrot, and, while you're at it, four-on-the-floor techno dance music, so you can feel the contrast. You should probably also get a teacher to teach you the fundamentals of music.
The rhythm of 4/4 time and strong beats on 2 and 4 comes from ancient traditions in West Africa, and spirituals, blues, jazz, gospel and rock are all evolved from the music of African-Americans, meaning residents of the United States of America. It is also prevalent throughout the New World wherever African immigrants settled.
It has nothing to do with drums, per se, because this strong rhythm is found in a capella singing traditions of African immigrants to the New World and persists to this day.
The musicological term for this is syncopation, which literally means "staggering", because Western musicologists consider this an interruption of the straight Western European rhythm.
Western classical and folk music, meaning that from Western Europe, places the strong beat on the first beat of each measure, and all subsequent beats are less strong. Many kinds of modern music, such as Mexican music, which I'm somewhat familiar with, still uses this Western-European beat. But the African-American syncopation appears in any genre of music that is ultimately influenced by that style.
In rock and pop music based on the style of the USA, it's the snare drum on the 2 and 4 that make what we call the "backbeats" which are the strong beats. The bass drum and the bass guitar don't play the strong beats.
Just let me hear some of that rock and roll music
Any old way you use it
It's got a backbeat, you can't lose it
Any old time you choose it
It's gotta be rock and roll music
If you want to dance with me