Cutting patterns comes with the symbols that are there to help you with your sewing project. Here are the most common symbols and terms used.
GRAIN LINE: Usually it is displayed as an arrow to identify the direction the paper pattern pieces should sit over the grain of the weave. The grain line of the fabric is the same as the direction of the selvage edges. Selvage edges are the outside edges of the fabric (usually white with writing on it)
NOTCHES: These are the marks on the cutting lines. Notches often identify where the two pieces/panels are matching. They also identify the location of pleats/gathering, zip, dart openings and end of stitch line. You can get single, double, and triple notches.
DOTS: These show where darts, zips or pockets are to be added.
LINES: Buttons and buttonhole positions are shown by short lines.
CUTTING LINES: A solid line outside the pattern.
SEWING LINES: A dotty line to indicate where the sewing occurs.
SEAM ALLOWANCE: The distance between the cutting line and the sewing line. Usually it is 1cm-1.5cm. Be aware of seam allowance when sewing!
I hope that this have been useful to you!