can i use concrete instead of mortar

Well, both concrete and mortar are used in construction, but they serve different purposes. Concrete is used for larger structural projects because it's stronger. It's composed of cement, sand and generally a coarse aggregate that makes it more durable.

Mortar, on the other hand, is typically used to hold bricks, stones, or blocks together in a structure. It's made up of a mixture of cement, lime and sand, and it's less durable but more flexible than concrete. This flexibility allows it to adjust to slight shifts in the foundation without cracking.

Exactly. If you use concrete instead of mortar in a brick or block wall, for example, the wall could become too rigid and might crack over time, especially in areas prone to ground movement. It's vital to use the right materials in the right places for the longevity and safety of your construction.