When you've studied and used the instructions and been able to find a scanned page on the Digitalarkivet that you'd like to capture as a URL to share with someone else to ask their assistance or save for your family history documentation - just copying the URL that your browser shows will NOT provide a working link for longer than about 1/2 an hour -- it only works very temporarily.
Working direct links to the scanned images on the Digitalarkivet can be copied and pasted from the desired page from a display option available. At the top of the scanned image page is an option labeled "Bildeinformasjon:" [Norwegian version]/"Image Information"[English version] which is by default set to "Ingen" [Norwegian version]/"None" [English version]. Change that and magic is available. Of the three options I like "Øverst" [Norwegian version]/"On top" [English version] because it puts the additional information across the top of the page and is usually easier for me to see.
The first line "Kildeinformasjon:" [Norwegian version]/"Source information" [English version] is a really nice summary of the source of the information and is wonderful to have for making detailed source citations, footnotes, etc.
The second line "Permanent sidelenke:" [Norwegian version]/"Permanent pagelink" [English version] is the best line to capture if you want to save the exact URL location or share the actual scanned image and the source information. It allows the full capabilities for zooming in and out to best view the image and informs the recipient of the exact location, book and other details to be able to find WHERE you found the information.
The third line "Permanent bildelenke:" [Norwegian version]/"Permanent imagelink" [English version] is the best used to print a copy of the image or to save a copy of the image in a jpg format computer file. This line does NOT also capture the source information and therefore is NOT the best line to copy to share online when requesting help or assistance in deciphering the image found.
Your questions are best answered by looking up the meanings of the column headings on the page...
Good information about translating the formats of Norwegian parish church records during various time periods, many of the basic terms used and understanding how to use the information should be studied at this web site -http://homepages.rootsweb.com/~norway/na20.html
Also use a online list such as this to decipher any specific words - http://home.online.no/~otjoerge/files/word.htm
Lutheran confirmations typically happened not long after when the child became a teenager. Often a range of years must be studied.