What does 数詞 (すうし, suushi) mean?

日本(にほん)語(ご)の数詞(すうし)は種類(しゅるい)が多(おお)い。

Japanese has many types of numeral counters.

助数詞(じょすうし)と数詞(すうし)の使(つか)い分(わ)けを学(まな)んだ。

I learned how to distinguish between counters and numerals.