When I was a kid, folks wore their “Sunday best” to church. Ritual attire included nice shoes, a good dress (Or pants and shirts for the boys), a Sunday hat and Sunday gloves. The minister wore a robe (so you could tell him apart for the rest of the men). Dads wore suits. Moms were dressy. People had special clothing for baptisms and confirmation. This, for that era and in that religion was ritual dress.
In the Wiccan community today, there is no standard dress code, although different traditions may have guidelines. For example, black robes for initiations and elevations, and white robes for funerals. The idea of changing from street clothes to ritual garb is both psychological and practical; moving from daily life to the spiritual life through the act of altering one’s attire touches on the psyche and wearing clothing that is cleansed and consecrated (after your spiritual bath) ensure that you won’t carry any excess negativity into the circle. Where some groups require that you wear special cords and jewelry, other groups insist that all be equal within the circle environment and only the high priest/priestess may wear something different or unusual. There are groups where rank is not an issue and everyone wears what they like, or all wear the same color but in different styles, and therefore you really have no idea what rank anyone is. Then there are groups where individuals of different elevation wear matching colors indicative of their status. As robes are not always practical, there are also magickal people who may wear something different or special for ritual, but it doesn’t flap around and threaten to snare every candle flame in the room. Finally, there are those that don’t wear anything at all, called skyclad. Although prominent in Gardner’s time due to his influence, skyclad has falled out of favor in most Wiccan groups. Like other Wiccan magickal tools, robes, cords, vestments and jewelry should be cleansed frequently, then cleansed, consecrated, and blessed before use.