Plastic packing bag sealing, 3 sides forming, sealing and 4 sides sealing what does that mean?
If you heat it on both sides of the bag, it is the three side seal. If the sides of the bag are all sealed, it is four sides. Don't understand, you can ask.
See the bottom of the bag, I use the arrow to indicate the sealing line, no, like this kind of bag, it is one side seal, also can call bottom seal
You should ask three sides and four sides. See the picture below.
