A pen is a common writing instrument that applies ink to a surface, usually paper, for writing or drawing. Early pens such as reed pens, quill pens, dip pens and ruling pens held a small amount of ink on a nib or in a small void or cavity that had to be periodically recharged by dipping the tip of the pen into an inkwell. Today, such pens find only a small number of specialized uses, such as in illustration and calligraphy. Reed pens, quill pens and dip pens, which were used for writing, have been replaced by ballpoint pens, rollerball pens, fountain pens and felt or ceramic tip pens. Ruling pens, which were used for technical drawing and cartography, have been replaced by technical pens such as the Rapidograph. All of these modern pens contain internal ink reservoirs, such that they do not need to be dipped in ink while writing.

लेखणी, किंवा पेन ही एक वस्तू आहे, ज्याद्वारे कागदावर शाई लिहिली जाते. रीड पेन, फेदर पेन, फाउंटन पेन, बॉल पॉइंट पेन अशा अनेक प्रकारचे लेखणी प्राचीन काळापासून वापरले जाते. रीड पेन, क्विल पेन, डिप पेन आणि रुलिंग पेन यांसारख्या सुरुवातीच्या पेनमध्ये निबवर किंवा लहान पोकळी किंवा पोकळीत थोड्या प्रमाणात शाई धरली जात होती, जी वेळोवेळी पेनची टीप शाईच्या विहिरीत बुडवून पुन्हा चार्ज करावी लागते.