Comparison operators are essential elements in programming that allow you to compare values and expressions, producing boolean results (either true or false). They are commonly used in conditional statements and loops to make decisions and control the flow of a program. PHP provides various comparison operators to cater to different comparison scenarios. Below are some of the most commonly used PHP comparison operators: 

Equal (==): The "equal" operator checks if two values are equal and returns true if they are, regardless of their data types. 

$a = 10;

$b = '10';

if ($a == $b) {

    // This condition is true because 10 and '10' are considered equal.

}

Identical (===): The "identical" operator checks if two values are equal and have the same data type. It returns true only if both conditions are satisfied. 

$a = 10;

$b = '10';

if ($a === $b) {

    // This condition is false because $a and $b have different data types.

}

• Not equal (!=) or (<>): The "not equal" operator checks if two values are not equal and returns true if they are different.

Example:

$a = 10;

$b = 5;

if ($a != $b) {

    // This condition is true because $a and $b are not equal.

}

• Not identical (!==): The "not identical" operator checks if two values are not equal and do not have the same data type. It returns true only if either condition is not satisfied.

Example:

$a = 10;

$b = '10';

if ($a !== $b) {

    // This condition is true because $a and $b have different data types.

}

• Greater than (>): The "greater than" operator checks if the left operand is greater than the right operand and returns true if it is.

Example:

$a = 15;

$b = 10;

if ($a > $b) {

    // This condition is true because 15 is greater than 10.

}

• Less than (<): The "less than" operator checks if the left operand is less than the right operand and returns true if it is.

Example:

$a = 5;

$b = 10;

if ($a < $b) {

    // This condition is true because 5 is less than 10.

}

• Greater than or equal to (>=): The "greater than or equal to" operator checks if the left operand is greater than or equal to the right operand and returns true if it is.

Example:

$a = 10;

$b = 10;

if ($a >= $b) {

    // This condition is true because $a is equal to $b (10) and greater than or equal to it.

}

• Less than or equal to (<=): The "less than or equal to" operator checks if the left operand is less than or equal to the right operand and returns true if it is.

Example:

$a = 5;

$b = 10;

if ($a <= $b) {

    // This condition is true because $a is less than $b (10) and equal to it.

}

These comparison operators are fundamental tools in PHP programming, enabling you to perform various logical checks and implement conditional behaviors in your code. Understanding their usage is crucial for writing effective and efficient PHP scripts. 

PHP logical operators are used to perform logical operations on boolean values, or the results of comparison operations, to make more complex decisions in your PHP code. They allow you to combine multiple conditions and control the flow of your program based on the evaluation of those conditions. PHP provides three main logical operators: "and" (&&), "or" (||), and "not" (!). Let's explore each of them:

1. Logical AND (&&):

The logical AND operator returns true only if both operands are true. If either one or both operands are false, it will result in false.

Example:

```php

$a = true;

$b = false;

if ($a && $b) {

    // This condition is false because $b is false, and both operands must be true for the condition to be true.

}

```

2. Logical OR (||):

The logical OR operator returns true if at least one of the operands is true. It will only return false if both operands are false.

Example:

```php

$a = true;

$b = false;

if ($a || $b) {

    // This condition is true because $a is true, and only one operand needs to be true for the condition to be true.

}

```

3. Logical NOT (!):

The logical NOT operator negates the boolean value of its operand. If the operand is true, the NOT operator will return false, and if the operand is false, it will return true.

Example:

```php

$a = true;

if (!$a) {

    // This condition is false because the NOT operator negates $a (true), resulting in false.

}

```

Logical operators are especially useful when combined with comparison operators, allowing you to build more intricate conditions in your PHP scripts. You can also use parentheses to group conditions and control the order of evaluation when using multiple logical operators together.

Example:

```php

$a = 10;

$b = 5;

$c = 7;

if ($a > $b && $a > $c) {

    // This condition is true if $a is greater than both $b and $c.

}

if ($a > $b || $a > $c) {

    // This condition is true if $a is greater than at least one of $b or $c.

}

if (($a > $b && $b > $c) || ($a > $c && $c > $b)) {

    // This condition is true if $a is greater than $b and $b is greater than $c, or $a is greater than $c and $c is greater than $b.

}

```

By understanding and effectively using PHP logical operators, you can create more sophisticated and flexible decision-making processes in your PHP programs.