What does this statement mean?

[Debora Cadene]

I found this write up this morning on Family Handiman, and was wondering what it actually means in English.  I do plan on "attempting" to make some ground blinds, and will need to do framing after I learn how, but understanding this explanation might be helpful.

Lets say the one wall is 5 feet wide, and 8 feet tall.  Is a linear foot, just a foot...so would this be 5 linear feet, with me needing 5 studs.  And when it says 5 linear feet of plate material per linear feet..., does that mean 5 boards per regular foot?...total 6 boards per foot equaling 30 boards for a 5 x 8' wall???  Does plate material include the 2x4's for the roof too?  

Use this formula to order framing materials

You don’t need a math degree to estimate framing materials for walls. Here’s a formula that works every time, no matter how many doors, windows or corners your walls have:

• One stud per linear foot of wall.
• Five linear feet of plate material (bottoms, tops and ties) per linear foot of wall. It’ll look like too much lumber when it arrives, but you’ll need the extra stuff for corners, window and door frames, blocking and braces. Set aside the crooked stuff for short pieces.

[R. E. Woods]

You would need six 8 ft boards for studs and one 10 ft board (cut in half) to make the top & bottom plates for each 5 by 8 wall.

[Russ Haynes]

Check your local code to see if studs need to be 16" on center. You can always make the wall beefier by doing them 12" or 14" on center.