Sketching

In SolidWorks, you can create parts by sketching 2D profiles & 3D Profiles.
Sketch is the base of the most features.
Without sketching you can't use most of the features.

There are 2 Types of Sketch 2D & 3D :

2D Sketch :

2D Sketch is used for creating simple shapes by extruding revolving,etc them into 3D shapes.
In 2D sketch you must first select a plane to sketch on.

3D Sketch :

3D sketch does not required plane to sketch on. Used to create complex geometry that would be difficult or impossible to create with a 2D sketch.
Some common use cases for 3D sketches include creating complex curves for surfaces, modeling pipe

Sketch Plane :

Sketch Plane is the plane which your are sketching on. The most common planes are the Front, Top, and Right planes.

Sketch Tools :

SolidWorks provides a variety of sketch tools to create different types of geometry. The most common sketch tools include:

Line: Draws a straight line between two points.
Circle: Draws a circle with a specified diameter or radius.
Rectangle: Draws a rectangle with a specified width and height.
Arc: Draws a curved line between two points.
Spline: Draws a smooth curve through a series of points

Sketch Constraints:

Constraints are used to control the size and position of sketch geometry. When you create sketch entities, SolidWorks automatically applies default constraints. You can add additional constraints or remove constraints as needed. The most common sketch constraints include:

Coincident: Forces two sketch entities to share the same point.
Tangent: Forces a curve to be tangent to a line or another curve.
Equal: Forces two dimensions to be equal in size.
Parallel:Forces two lines or edges to be parallel.
Collinear: Force two lins or edges to be inline
Fix: Force to fix the current position of entities
Mirror: Force to Mirror entities about a plane or line

Sketch Dimensions:

Dimensions are used to specify the size and position of sketch geometry. You can add additional dimensions or remove dimensions as needed. To add a dimension, select the sketch entity and then click on the “Smart Dimension” tool in the toolbar. Then, click on the location where you want to place the dimension.