Informally, a group consists of a number of stones of one colour, hanging together as if effectively connected. They are a functional unit on the board, occupying and influencing a certain area.
In this game, 100 stones have been played. The following stones are commonly called a "group"
- the nine white stones in the lower left
- the three white stones in the upper left
- the black structure in the upper middle
- the black stones in the upper right
- the unmarked white stones running from the upper right to the centre
- the ten white stones in the lower right
- the black stones at the bottom form two groups that are likely to become one, if they swallow the five white stones dividing them, or connecting via one of the points a
The Chinese term, 块（塊）kuài, is not a noun, but a measure word (aka classifier, counter), i.e. it acts as a unit in which a noun is counted. The noun used in this context is 棋 qí, here meaning "stones“. Measure words must be combined with a numeral, or a demonstrative pronoun, or both. E.g.: 一块棋 yí kuài qí, "a group (of) stones, one group (of) stones", 这两块死棋 zhè liǎng kuài sǐ qí, "these two dead groups". Primary meaning of kuài is "a chunk of (something)", but also "a piece (e.g. of land)".
The term group is sometimes also used to refer to collections of stones which are all solidly connected together. In those contexts where it matters, such as in rules texts or go theory, the terms chain or string are usually used instead, to differentiate this concept from the more vague group concept described above.