An individual number which is the core of the data: e.g.
Dimensions define how the observations divide up different slices of the data e.g.: by employment status, age, location and date. (The ONS generally don't consider locations or dates to be dimensions; but we treat them in a very similar manner).
Each observation will have values associated with each dimension: the labels might be 'unemployed', 'aged 16-21', 'Little Linford' and '2010'
A replacement or an addendum to an observation. The 84 might be replaced by a datamarker ".." to mean suppressed, or have a trailing 'p' to say that it's provisional.
The cells in the spreadsheet that represent the title of something. e.g. For a time dimension, the cells containing the years.
A method on a bag which chooses cells from a table or other bag, and returns a bag.
A page in an Excel workbook.
An individual item in a spreadsheet. e.g. the cell at position C3.
The length of a time period. e.g.
A function which takes a cell and returns True or False depending on the cell's contents.
UP, DOWN (and their synonyms ABOVE, BELOW) and LEFT and RIGHT.