Help on the differrences please

There's no difference other than they are different ways to express the same thing. Much the same way as you can express time differently. Such as you can say that it is 6:15 or you can say that it is a quarter after 6. Same thing.

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Coordinates can be expressed in several different formats.

They are most commonly Degrees Minutes Seconds (DDD MM SS), Decimal Degrees (DDD.DDDD), or Degrees Decimal Minutes (DDD MM.MMM).

The last format is the most common in current GPS models. The second one is the one we use in Custom POI files.

Here are some examples of the same coordinates expressed in different formats.

Degrees, Minutes and Seconds
DDD° MM' SS.S"
N 32° 18' 23.1" W 122° 36' 52.5"

Decimal Degrees
DDD.DDDDD°
N 32.30642° W 122.61458°

Degrees and Decimal Minutes
DDD° MM.MMM'
N 32° 18.385' W 122° 36.875'

so what your saying is the one i should use is DD format i want to start getting into more customs poi stuff or is it DMS lololol what one i should use for custom pois thanks

What Motorcycle Mama was saying is that coordinates are normally expressed using three different types of notation all describing the same physical point. The method you use will depend on the device requirements.

If your device uses decimal notation, then use that format. If it uses DMS use that notation. Most GPS units use decimal notation according to the WGS 1984 Datum.

It's the same as radian math, except in units of 60 instead of 90 degrees. You can do the conversion manually or use a free conversion program like this one.

http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html

It seems to me that there is very little similarity between converting from DDD MM SS.S to DDD.DDDD and converting from radians to DDD.DDDD

In the former you divide seconds by 60, add the result to the minutes, then divide the total minutes (including fractional part) by 60, add the result to the degrees.

Or you could divide the seconds by 3600, add the result to the degrees, then divide the minutes by 60 and add the result to the DDD.DDDD obtained from the original DDD and SS.S/3600

In the latter you simply multiply radians by 180/PI and the conversion is done.