Ahorro_A tag is a tag structure used for that instance of the AOI. An AOI needs tags created for the memory to execute the instruction. You can't delete the tag without deleting the AOI that uses it.
In this case Ahorro_A is a tag structure of type AHORRO_ON which was created with the AOI. Elements of the tag will include Ahorro_A.Num_de_paso, Ahorro_A.Bit_A, and all other tags used in the AOI. Depending on what the AOI does, you might or might not need a separate tag for each of multiple instances.
I'm not sure what you mean by 0-1 value. You might have an output bool on or off, and you could have a real output with values in the 0-1 range, but that's not shown in the image.