how to make two items side by side in css code example

Example 1: how to align two divs side by side

.wrapper {
    display: flex;
    flex-wrap: wrap;
}

.wrapper>div {
    flex: 1 1 150px;
    height: 500px;
}

Example 2: css position side by side

/************ How to position elements side by side? ***************/

/* We can use the property "display: inline" to place blocks of elements 
side by side, however, this does not allow an aesthetic alignment of all 
elements and we can't position a stack or group of two or more blocks 
beside another block. For example, placing a header and a paragraph on 
the left side of an image. For that, we use the "float" property.
This tells the other elements to make room for the element that is 
"floating" in a certain position, with the minimum disturbance to the 
flow of the document (packing everything tightly) */

img {
  float: left;   /* The image will float on the left side of the text*/
}

h3 {
  text-align: left;
}

p {
  text-align: left;  
}


/****************** How to isolate this effect? **********************/

/* For example, in case we want to keep the image and the header side 
by side, but making sure the paragraph is kept below the image. In this 
case, we can simply use a property that will prevent that any other 
element can be placed on the left of the <p> element. That way, as the 
pieces are stack throughout the document, the browser will simply put 
the <p> element below the "floating" image. */

img {
  float: left;
}

h3 {
  text-align: left;
}

p {
  text-align: left;
  clear: left;     /* This will stop any other element from being placed on it's left side */
}