Maceration and Infusion are the same thing – both involve immersing botanicals in alcohol and leaving to soak until the desired flavours have leached out.
We separate the two terms as Maceration being part of the distilling process, while Infusion tends to be a term used to describe something that happens to an end spirit after distillation. That is not industry standard, just our way of avoiding confusion as almost always on labels when something has been “infused” it refers to an extra step that’s happened after distillation.
We also separate the two as it’s possible to infuse the botanicals into a spirit through other methods than immersing them (e.g., Vapour Infusion).