Selects odd elements, zero-indexed. See also even.
In particular, note that the 0-based indexing means that, counter-intuitively, :odd selects the second element, fourth element, and so on within the matched set.
Because :odd is a jQuery extension and not part of the CSS specification, queries using :odd cannot take advantage of the performance boost provided by the native DOM querySelectorAll() method. To achieve the best performance when using :odd