Is there any difference between using multiple if statements and else if statements?

Yes, potentially. Consider this (C#, Java, whatever):

int x = GetValueFromSomewhere();

if (x == 0)
{
    // Something
    x = 1;
}
else if (x == 1)
{
    // Something else...
}

vs this:

int x = GetValueFromSomewhere();

if (x == 0)
{
    // Something
    x = 1;
}
if (x == 1)
{
    // Something else...
}

In the first case, only one of "Something" or "Something else..." will occur. In the second case, the side-effects of the first block make the condition in the second block true.

Then for another example, the conditions may not be mutually exclusive to start with:

int x = ...;

if (x < 10)
{
    ...
} 
else if (x < 100)
{
    ...
}
else if (x < 1000)
{
    ...
}

If you get rid of the "else" here, then as soon as one condition has matched, the rest will too.

It has to do with efficiency and your needs. If statements are executed independent of one another; each one will run. Else if statements only execute if the previous ifs fail.

if (x == 0) {
    // 1
}


if (x >= 0) {
    // 2
}

if (x <= 0) {
    // 3
}

Above code will produce different value than the code below for x=0.

if (x == 0) {
    // 1
} else if (x >= 0) {
    // 2
} else {
   // 3
}

In the first case all the statements 1, 2, and 3 will be executed for x = 0. In the second case only statements 1 will be.