Brass: supplied with the printer, valid for printing the most common materials (PLA, PETG, ABS, ETC). They have better thermal conductivity than steel nozzles
Steel: suitable for printing objects that will be in contact with food or with the mouth or respiratory tract since it does not contain lead, however, they have a lower thermal conductivity than brass, so they are not recommended for daily use with common materials
Hardened steel: suitable for printing with materials that contain chips of hard materials such as carbon fiber, metal, etc. Their durability with these materials will be longer than a standard brass nozzle, however, they have a lower thermal conductivity than brass, so they are not recommended for daily use with common materials
Silver Copper: suitable for printing at high temperature (>300º) supporting up to 500º, its outer nickel coating prevents the material from adhering to the nozzle. They have up to 3 times higher thermal conductivity than brass nozzles, as well as twice the hardness, so they perform better than brass nozzles even for printing common materials such as PLA, PETG, ABS
<0.4mm: suitable for maximum detail at the expense of increased printing times
0.4mm: most common size, with a good compromise between printing time and detail
0.5-0.6mm: nozzles commonly used to increase printing speed without a great loss of detail, also used for materials with large traces such as wood filament.
>0.6mm: used for large prints, the loss of detail is notable. For these sizes, it is recommended to have a volcano-type hotend, since the amount of material to be melted per second can be too much for a normal hotend