The Browse function allows you to search for someone through location, and to view households surrounding that of your ancestor. It also allows for studies of particular districts.
For example, going from Browse into Dublin, then into the list of DEDs, you can click on one, eg Arran Quay, and a list of the streets/townlands in that DED will appear. If you see one that looks familiar, clicking on that will give you a link to the occupants of that street or townland, and you can browse through these until you find the person you seek. Then you can click on occupants of the house, and further click on the original census form images.
Browsing the street/townland will give you access to neighbours of your ancestor. The browsing facility is also very useful for anyone trying to get a picture of a particular area, such as the main street of a small town, eg Clondalkin.
Browse backwards through breadcrumbs
The Residents of a Household page, which you get to from a person search, will have, above the list of occupants, what are known as "breadcrumbs" e.g. Home / 1901 or 1911 / All counties / Dublin / Arran Quay / Oxmantown Road / Residents of a house.
By clicking on the street (Oxmantown Rd.) or DED (Arran Quay), you can get back to a list of surnames on the street, or streets/townlands in the DED, and look at neighbours on the street/ townland, or occupants of nearby streets/townlands.