Groove is a more generalized concept of flow and texture. It refers to how flow and texture is applied to match a piece of music in a broader context. A pattern with excellent groove will typically achieve a blend of transcription accuracy, connotation, and an abstractly desired feel. Effective use of transcription accuracy and connotation can still describe a very large range of possible approaches to a particular piece of music. Groove makes the distinction about the quality of the feel, such as a smoothing and relaxing pattern, versus a slick and funky pattern, versus an intense, chaotic pattern. Think of it as how your fingers "dance" along the keyboard.
Because of how qualitative the definition of groove is by nature, we will directly jump to a concrete exmaple, where we deconstruct an approach on a small section of a piece of music. Note that in these examples, we are focusing more on the background instrumentation for reference: the keyboard, electric guitar, bass guitar, and drums. We are largely going to be ignoring the vocals and turntable in the forefront.
In this first version, we have very basic rhythms and a fairly straightforward layering technique. We primarily focus on the electric guitar and keyboard. There are some other small subtle tricks, such as having  wherever there are snare hits to implicitly provide that connotation as well. The last measure switches focus to the bass guitar for variety on the fill transition. Notice that while there is a really nice syncopated rhythm, it is quite sparse. This would be an appropriate baseline approach to a simpler chart.
In this second version, once again the rhythm is very basic. Our focus this time is the bass guitar. However, notice that most of the doubles are placed on the bass guitar's accented notes. The doubles are not the result of layering by any added instrument. This rhythm is dramatically different from the first version, but due to the syncopation, still has a nice funk feel, with a little bit more of a driving rhythm. An approach that begins with this as a baseline can be very fitting for this style of music because of how important the bass guitar is, especially with a slap bass. In this particular song, the bass guitar isn't especially strong, so the sound is not only muddy, but is further made ambiguous by the fact that kick drum is often offset from it.
In this third version, we focus solely on the percussion. Obviously, such a reductive take on this song would be exceptionally bland and uninteresting, but it is important to recognize certain traits of this example. Specifically, that what gives this song its funky syncopated feeling is not in fact the percussion, but the other instruments. The drum merely acts as the foundation that holds everything together, with consistent 8th notes on the hi-hat. Those 8th notes are not very interesting to play, and they are often times detrimental to the syncopated feel we are looking for in a song like this. In addition, the kick drum is very muddy and difficult to make out behind all the other sounds. A common trap that a lot of artists fall into is choosing to layer percussion simply because it is the most obvious thing to transcribe and layer, without taking into consideration how it would impact the feel of the patterns.
In this final version, we attempt to combine all of the best traits of the previous examples. We liberally utilize some jack theory to help build and release tension to highlight the syncopated rhythms. The rhythm is more dense, but it selectively chooses instrumentation and layers in such a way that it preserves the syncopated feel that makes the song funky in the first place. There is a little bit of misdirection in pitch relevance as well: Reversing the pitch direction in a controlled manner creates more interesting contrasting patterns while maintaining a balance between the left and right hands.
This is merely one of many possible deconstructions of this song. Keep in mind that when evaluating your groove, you should have a clear target and try to adjust your patterns in such a way that the particular qualitative feel is achieved.
One factor to pay attention to in particular is how difficulty correlates to your groove. The density of your notes can affect your feel just as much as the patterns themselves can. Note density imparts physical strain on the fingers and depending on the skill level of the player, mental strain as well. When planning your chart, make sure you understand your target groove so that you can appropriately choose which layers to follow in order to achieve the desired groove while keeping a reasonable difficulty progression and maintaining your motifs.