I agree with the recommendation in the previous answer to view the cited collection in the online catalogue of the archive which holds the record, in this case, TNA. This answer is intended as a supplement to show how you can get even more information, and to make the answer more generally useful.
Basics of Archival Arrangement
The US National Archives describes the levels of archival arrangement as follows:
In all large archival depositories there can be distinguished,
usually, at least five levels of arrangement:
- Arrangement at the depository level -- the breakdown of the depository's complete holdings into a few major divisions on the
broadest common denominator possible and the physical placement of
holdings of each such major division to best advantage in the
building's stack areas. This major division of holdings is usually
reflected in parallel administrative units (divisions or branches in
the depository organization that are given responsibility for these
- Arrangement at the record group and subgroup levels -- the breakdown of the holdings of an administrative division or branch (as
these may have been established on the first level) into record groups
and the physical placement of these in some logical pattern in stack
areas assigned to the division or branch. This level should include
the identification of natural subgroups and their allocation to
established record groups.
- Arrangement at the series level -- the breakdown of the record group into natural series and the physical placement of each series in
relation to other series in some logical pattern.
- Arrangement at the filing unit level -- the breakdown of the series into its filing unit components and the physical placement of
each component in relation to other components in some logical
sequence, a sequence usually already established by the agency so that
the archivist merely verifies and accepts it.
- Arrangement at the document level -- the checking and arranging, within each filing unit, of the individual documents, enclosures and
annexes, and individual pieces of paper that together comprise the
filing unit and the physical placement of each document in relation to
other documents in some accepted, consistent order.
References from The US National Archives (NARA) will include a Record Group followed by a number, where TNA uses a government departmental reference code (e.g. HO = Home Office) but the principles are similar. In this case, we have HO 127 Piece 143, and the question is, what is the scope of the records contained within that piece (subgroup)?
Help at findmypast
From the Record Page for the individual search result, look at the information underneath the record details:
Class: HO 27; Piece: 143; Page: 213
Clicking on the Learn More link, or clicking on the Title England & Wales, Criminal Registers, 1791-1892 will take you to the main search page for the collection. From there, you can read the About the Database. You can also learn more about how the records are arranged on Ancestry itself by looking at the browse box on the right-hand side of the page.
In this case, Ancestry has broken out each county separately, and has not given you any archive references in the listing in the browse box. Some databases offer more information.
If you are in the image viewer, you can find out the archive reference by pulling out the side panel in the image viewer:
The panel recaps the information shown under the record page, so you don't have to switch back and forth between two tabs to read it and look at the image. However, it may not have all of the information you can find on the record page (there's no link to the learn more information on the main search page).
Once you have the archive reference, go to the original archive to find out more, as already suggested.
Research guidance at TNA
Via TNA's Discovery, look for Help With Your Research. The page "How to look for records of ... Crime, prisons and punishment 1770-1935" lists the series included in the collection with links to the top level of the hierarchy (in this case, you are looking for HO27). Like at Findmypast, you can find even more information by following links to related research guides shown on the right-hand side of the page.
I also recommend navigating to your piece within the hierarchy at TNA, since it gives you an overview of how records are arranged.
If you are searching via Google, try looking for the collection title plus "scope and content" and "finding aids" to determine the scope of a group or sub-group of records. Also search for the title of the entire group of records by itself to find articles about the collection and research guides that mention it.