This may be a problem that is easy to be ignored. First, we need to be clear:
In MySQL, AND takes precedence over OR. That is to say, without the limitation of parentheses (), the AND statement is always executed first AND then the OR statement.
For example:

select * from table where condition1 and condition2 or condition3
 Equivalent to
 select * from table where (condition 1 AND 2) OR condition 3

select * from table where condition1 and condition2 or condition3 and condition4
 Equivalent to
 select * from table where (condition 1 AND condition 2) OR (condition 3 AND condition 4)

Here are some examples:
Test table data:

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for book
-- ----------------------------
DROP TABLE IF EXISTS `book`;
CREATE TABLE `book`  (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `name` varchar(25) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
  `author` varchar(25) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
  `price` decimal(10, 2) DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of book
-- ----------------------------
INSERT INTO `book` VALUES (1, 'PHP', 'mate', 21.00);
INSERT INTO `book` VALUES (2, 'JAVA', 'kaven', 23.00);
INSERT INTO `book` VALUES (3, 'JAVA senior', 'loose', 45.00);
INSERT INTO `book` VALUES (4, 'GO', 'jim', 46.00);
INSERT INTO `book` VALUES (5, 'GO Design', 'json', 76.00);
INSERT INTO `book` VALUES (6, 'PHP Advanced programming', 'bate', 67.00);
INSERT INTO `book` VALUES (7, 'Python', 'jim', 66.00);
INSERT INTO `book` VALUES (8, 'Python Design', 'mali', 54.00);
INSERT INTO `book` VALUES (9, 'GO programming', 'kaven', 86.00);
INSERT INTO `book` VALUES (11, 'Python3', 'jim', 55.00);

SET FOREIGN_KEY_CHECKS = 1;

Query method 1:

SELECT * FROM book WHERE author='jim' OR author='json' AND name='PHP';

The above query is equivalent to:

SELECT * FROM book WHERE author='jim' OR (author='json' AND name='PHP');

Then the above query results are easy to understand.
Query method 2:

SELECT * FROM book WHERE name='PHP' AND author='jim' OR author='json';

The above query is equivalent to:

SELECT * FROM book WHERE (name='PHP' AND author='jim') OR author='json';

Query method 3:

SELECT * FROM book WHERE name='GO' AND (author='jim' OR author='json');

This is easy to understand. Understand the priority of and or. These queries are not "understanding confusion".