NER Tagging

while POS Tagging assigns tags to each word, NER Tagging tags the category of usage of multi-word spans.
NER Tagging needs to label spans of text, which means that there is ambiguity in type.
BIO Tagging BIO Tagging will tag each word: where B begins a span, I, is inside a span, and O outside a span. So tags per word still apply, but we can extract span information as well.
(job - gender + gender ) = job (captial - country + country) = captial