Cutting insert, cutting tool, and method for manufacturing machined product

A cutting insert comprising:

• a main body section elongated in a direction from a rear side to a front side;
• and
• a cutting section located in front of the main body section and comprising
• a top surface;
• a bottom surface;
• a first side surface located at the front side and between the top surface and the bottom surface;
• a second side surface located between the top surface and the bottom surface and adjacent to the first side surface;
• a front cutting edge disposed along a ridge line of the cutting section at an intersection between the top surface and the first side surface;
• a lateral cutting edge disposed along the ridge line at an intersection between the top surface and the second side surface, the lateral cutting edge having an ascending incline from the front cutting edge toward the main body section;
• and
• a corner cutting edge disposed between the front cutting edge and the lateral cutting edge,
• wherein
• the lateral cutting edge comprises a first region near to the front cutting edge and extending in an ascending incline from the corner cutting edge toward the main body and a second region located to a rear of the first region;
• the first region and the second region each having a linear shape in side view, and an angle of inclination of the second region with respect to the bottom surface being larger than an angle of inclination of the first region with respect to the bottom surface.