What is the ball (rule 2.d) in Pickleball?

Section 2: Equipment

Pickleball paddles must conform to USAP specifications for sanctioned play. Key requirements include:

The combined length and width of the paddle, including edge guard and butt cap, shall not exceed 24 inches (60.96 cm). The paddle length shall not exceed 17 inches (43.18 cm).
There is no restriction on paddle weight, though most competitive paddles range between 7.0 and 8.5 ounces.
The hitting surface must be rigid and made of a smooth, non-compressible material. Common materials include graphite, carbon fiber, fiberglass, and composite polymers.
The surface must not contain holes, indentations, rough texturing, or any features that allow a player to impart additional spin beyond what a smooth surface provides. Anti-spin coatings and delaminated paddles are prohibited.
Only USAP-approved paddles appearing on the official Approved Paddle List may be used in sanctioned tournament play.

Pickleball uses a unique perforated polymer ball, distinct from any other racquet sport. Specifications include:

The ball must be a single, uniform color (excluding markings). Common colors are yellow, white, and orange.
The ball must have between 26 and 40 circular holes drilled through its surface.
Outdoor balls typically have 40 smaller holes, are harder, and are slightly heavier (approximately 0.9 oz / 25.5 g). Indoor balls typically have 26 larger holes, are softer, and are lighter (approximately 0.8 oz / 22.7 g).
The ball must be made of a durable molded material with a smooth surface. The diameter must be between 2.874 inches and 2.972 inches (73.0–75.5 mm).
Balls must appear on the USAP Approved Ball List for sanctioned play.

The net shall be at least 21 feet 9 inches (6.63 m) long, extending from one sideline to the other.
The net height shall be 36 inches (91.44 cm) at the sidelines and 34 inches (86.36 cm) at the center.
The net must be made of a mesh fabric that does not allow the ball to pass through it. The maximum mesh size is 1 inch square.
A center strap is used to secure the net at the proper center height of 34 inches.

Pickleball paddles must conform to USAP specifications for sanctioned play. Key requirements include:

The combined length and width of the paddle, including edge guard and butt cap, shall not exceed 24 inches (60.96 cm). The paddle length shall not exceed 17 inches (43.18 cm).
There is no restriction on paddle weight, though most competitive paddles range between 7.0 and 8.5 ounces.
The hitting surface must be rigid and made of a smooth, non-compressible material. Common materials include graphite, carbon fiber, fiberglass, and composite polymers.
The surface must not contain holes, indentations, rough texturing, or any features that allow a player to impart additional spin beyond what a smooth surface provides. Anti-spin coatings and delaminated paddles are prohibited.
Only USAP-approved paddles appearing on the official Approved Paddle List may be used in sanctioned tournament play.

Pickleball uses a unique perforated polymer ball, distinct from any other racquet sport. Specifications include:

The ball must be a single, uniform color (excluding markings). Common colors are yellow, white, and orange.
The ball must have between 26 and 40 circular holes drilled through its surface.
Outdoor balls typically have 40 smaller holes, are harder, and are slightly heavier (approximately 0.9 oz / 25.5 g). Indoor balls typically have 26 larger holes, are softer, and are lighter (approximately 0.8 oz / 22.7 g).
The ball must be made of a durable molded material with a smooth surface. The diameter must be between 2.874 inches and 2.972 inches (73.0–75.5 mm).
Balls must appear on the USAP Approved Ball List for sanctioned play.

The net shall be at least 21 feet 9 inches (6.63 m) long, extending from one sideline to the other.
The net height shall be 36 inches (91.44 cm) at the sidelines and 34 inches (86.36 cm) at the center.
The net must be made of a mesh fabric that does not allow the ball to pass through it. The maximum mesh size is 1 inch square.
A center strap is used to secure the net at the proper center height of 34 inches.