The earliest history of the Fountain pen can be traced back to the 10th century. It is generally used to fill ink with vials or straws such as eye drops. The earliest water storage pen was used until the 18th century. It was not until the early 19th century that Britain issued the first batch of patent certificates for water storage pens that it marked the official birth of Fountain pens.
Fountain Pen is a kind of pen writing tool mainly with metal as the pen body. It contains ink through a hollow pen tube, and then writes through a duck beak pen head through the action of gravity and capillary. The writing weight is different. Most pens can be refilled with ink, usually using vials or straws such as eyedrops.
Source: @finelinewilly